{"schemaVersion":"1.0","publisher":"脆弱性ナビ","origin":"https://zeijaku.ittrip.xyz","terms":[{"name":"CVE Program","url":"https://www.cve.org/legal/termsofuse","notice":"CVE content is used subject to the CVE Program Terms of Use. CVE is a trademark of The MITRE Corporation.","licenseText":"CVE content: Copyright The MITRE Corporation. CVE is a trademark of The MITRE Corporation.\nCVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.\nDisclaimers: ALL DOCUMENTS AND THE INFORMATION CONTAINED THEREIN PROVIDED BY MITRE ARE PROVIDED ON AN \"AS IS\" BASIS AND THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE MITRE CORPORATION, ITS BOARD OF TRUSTEES, OFFICERS, AGENTS, AND EMPLOYEES, DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION THEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE."},{"name":"NIST NVD","url":"https://nvd.nist.gov/general/faq","notice":"This product uses data from the NVD API but is not endorsed or certified by the NVD."},{"name":"JVN","url":"https://jvn.jp/contact/index.html","notice":"出典：JVN（JPCERT/CC・IPA）。原文は各レコードの参照先を確認してください。"},{"name":"CISA KEV","url":"https://github.com/cisagov/kev-data","notice":"Known Exploited Vulnerabilities catalog, CISA. CC0."}],"deliveryMode":"static","generatedAt":"2026-10-31T10:36:08.347Z","asOf":"2026-10-31T10:36:08.347Z","snapshotId":"7baa8ebb8bb7565076ea55ab","refreshIntervalHours":3,"staleAfterHours":6,"record":{"id":"CVE-2026-5821","aliases":[],"title":"Image Optimizer – Compress Images and Convert to WebP or AVIF：サービス停止","summary":"Image Optimizer – Compress Images and Convert to WebP or AVIFを使っている方が確認する情報です。公表文は「サービス停止」に関する問題を示しています。公開された対象範囲を下に日本語で示しています。","risk":"問題の種類についての一般的な説明：攻撃で処理が止まったり負荷が増えたりして、サイトや機能を利用できなくなるおそれがあります。この分類だけで情報流出も起きるとは判断できません。","product":"Image Optimizer – Compress Images and Convert to WebP or AVIF","category":"wordpress","component":"plugin","severity":"high","cvss":8.1,"cvssVersion":"3.1","cvssSource":"security@wordfence.com","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","affected":[{"product":"Image Optimizer – Compress Images and Convert to WebP or AVIF","range":"<= 1.7.4"}],"fixed":[],"steps":["「CVE-2026-5821」と現在の版を管理担当者・提供元へ伝え、この問題に対応した修正版が提供されているか確認します。下の問い合わせ文に記入すれば、そのまま依頼できます。対象範囲の上限から修正版の番号を推測しないでください。","ファイルとデータベースのバックアップを取り、管理画面の「ダッシュボード」→「更新」で該当プラグインの更新を実行します。更新が表示されない有料製品などは、購入先・開発元の正規の配布経路を利用してください。"],"references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-5821","label":"NVDの原文"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","label":"security@wordfence.com"},{"url":"https://research.cleantalk.org/cve-2026-5821","label":"security@wordfence.com"},{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve","label":"security@wordfence.com"},{"url":"https://www.first.org/cvss/v3.1/specification-document","label":"FIRST公式：CVSS 3.1の条件の定義"},{"url":"https://wordpress.org/documentation/article/plugins-screen/","label":"WordPress公式：プラグイン一覧"},{"url":"https://wordpress.org/documentation/article/site-health-screen/","label":"WordPress公式：サイトヘルスの情報"},{"url":"https://wordpress.org/documentation/article/updating-wordpress/","label":"WordPress公式：本体の更新"},{"url":"https://wordpress.org/documentation/article/dashboard-updates-screen/","label":"WordPress公式：更新画面"},{"url":"https://wordpress.org/documentation/article/manage-plugins/","label":"WordPress公式：プラグインの確認と更新"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-5821","label":"公式記録の識別番号"}],"publishedAt":"2026-07-02T06:16:14.220Z","modifiedAt":"2026-10-28T01:16:55.603Z","fetchedAt":"2026-10-31T01:47:38.469Z","exploitStatus":"unknown","sources":["NVD"],"originalText":"The Image Optimizer plugin for WordPress is vulnerable to arbitrary file deletion in versions up to and including 1.7.4. This is due to insufficient path validation in the Image_Backup::remove() function where backup file paths stored in post meta are used directly in file deletion operations without verifying they are within the uploads directory. The plugin stores backup file paths in the image_optimizer_metadata post meta field and trusts these paths completely when deleting backups on the delete_attachment hook. An authenticated attacker with Author-level access can edit the image_optimizer_metadata post meta on their own attachments via WordPress's Custom Fields interface, injecting arbitrary absolute file paths into the backups array. When the attacker subsequently deletes the attachment, the plugin calls File_System::delete() on each path without validation. This makes it possible for authenticated attackers, with Author-level access and above, to delete arbitrary files on the server within the web server's filesystem permissions, potentially leading to denial of service, data loss, or security degradation.","sourceTitle":"CVE-2026-5821","summaryMethod":"公開データの対象範囲・CVSS条件を日本語化し、製品ごとの一般的な操作手順を補足しています。個別の全文翻訳・環境診断ではありません。","state":"published","affectedDetails":[{"vendor":"elemntor","product":"Image Optimizer – Compress Images and Convert to WebP or AVIF","defaultStatus":"unaffected","versions":[{"version":"0","lessThanOrEqual":"1.7.4","versionType":"semver","status":"affected"}]}],"sourceSnapshots":[{"source":"NVD","modifiedAt":"2026-10-28T01:16:55.603Z","fetchedAt":"2026-10-31T01:47:38.469Z","state":"published"}],"sourceSummary":"Image Optimizer – Compress Images and Convert to WebP or AVIFにサービス停止に関する脆弱性情報があります。影響を受ける条件を確認してください。","sourceRisk":"処理の停止や過大な負荷により、サービスを利用できなくなる可能性があります。","guidance":{"schemaVersion":"1.0","method":"structured","reviewedAt":null,"reviewState":"unreviewed","summary":"Image Optimizer – Compress Images and Convert to WebP or AVIFを使っている方が確認する情報です。公表文は「サービス停止」に関する問題を示しています。公開された対象範囲を下に日本語で示しています。","risk":"問題の種類についての一般的な説明：攻撃で処理が止まったり負荷が増えたりして、サイトや機能を利用できなくなるおそれがあります。この分類だけで情報流出も起きるとは判断できません。","applicability":[{"text":"最初に「Image Optimizer – Compress Images and Convert to WebP or AVIF」を使っているか、開発元・製品名・バージョンを確認します。同じカテゴリの製品を使っているだけでは、この問題の対象とは限りません。","kind":"check","sourceUrls":["https://nvd.nist.gov/vuln/detail/CVE-2026-5821","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","https://research.cleantalk.org/cve-2026-5821","https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve"]},{"text":"公開データの対象範囲：Image Optimizer – Compress Images and Convert to WebP or AVIF — 1.7.4以下。この範囲に加え、下に記載する権限・構成などの条件も照合してください。","kind":"fact","sourceUrls":["https://nvd.nist.gov/vuln/detail/CVE-2026-5821","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","https://research.cleantalk.org/cve-2026-5821","https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve"]},{"text":"公表されたCVSS評価では、攻撃者は事前に一般利用者程度の権限を持つ必要があります。WordPressの「購読者」「投稿者」などの具体的な役割は、この値だけでは分かりません。","kind":"fact","sourceUrls":["https://nvd.nist.gov/vuln/detail/CVE-2026-5821","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","https://research.cleantalk.org/cve-2026-5821","https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve","https://www.first.org/cvss/v3.1/specification-document"]},{"text":"公表されたCVSS評価では、ネットワーク越しに攻撃が届く経路があります。あなたの環境がインターネットから到達可能かどうかは、公開設定を別に確認する必要があります。","kind":"fact","sourceUrls":["https://nvd.nist.gov/vuln/detail/CVE-2026-5821","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","https://research.cleantalk.org/cve-2026-5821","https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve","https://www.first.org/cvss/v3.1/specification-document"]},{"text":"公表されたCVSS評価では、攻撃者以外の利用者がリンクを開くなどの操作をしなくても、攻撃が成立し得ます。","kind":"fact","sourceUrls":["https://nvd.nist.gov/vuln/detail/CVE-2026-5821","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","https://research.cleantalk.org/cve-2026-5821","https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve","https://www.first.org/cvss/v3.1/specification-document"]}],"versionChecks":[{"text":"WordPressの管理画面にログインし、「プラグイン」→「インストール済みプラグイン」を開きます。「Image Optimizer – Compress Images and Convert to WebP or AVIF」と同じ製品名・開発元の項目を探し、表示されているバージョンを控えてください。停止中のプラグインも一覧に含めて確認します。","kind":"procedure","sourceUrls":["https://wordpress.org/documentation/article/plugins-screen/"]},{"text":"管理画面に入れない、または同じ名前の製品を判別できない場合は、下の問い合わせ文をサイトの制作会社・管理担当者に送ってください。名前が見つからないという理由だけで、安全とは判定しないでください。","kind":"procedure","sourceUrls":["https://wordpress.org/documentation/article/site-health-screen/","https://wordpress.org/documentation/article/plugins-screen/"]}],"actions":[{"text":"「CVE-2026-5821」と現在の版を管理担当者・提供元へ伝え、この問題に対応した修正版が提供されているか確認します。下の問い合わせ文に記入すれば、そのまま依頼できます。対象範囲の上限から修正版の番号を推測しないでください。","kind":"procedure","sourceUrls":["https://nvd.nist.gov/vuln/detail/CVE-2026-5821","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","https://research.cleantalk.org/cve-2026-5821","https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve"]},{"text":"ファイルとデータベースのバックアップを取り、管理画面の「ダッシュボード」→「更新」で該当プラグインの更新を実行します。更新が表示されない有料製品などは、購入先・開発元の正規の配布経路を利用してください。","kind":"procedure","sourceUrls":["https://wordpress.org/documentation/article/updating-wordpress/","https://wordpress.org/documentation/article/dashboard-updates-screen/","https://wordpress.org/documentation/article/manage-plugins/"]}],"temporaryMitigations":[{"text":"更新できない場合は、対象機能の停止や公開範囲の制限が使えるかを管理担当者と検討し、実施内容と更新予定日を記録してください。プラグインの「無効化」だけでこの脆弱性を防げるかは個別に確認が必要です。","kind":"procedure","sourceUrls":["https://wordpress.org/documentation/article/plugins-screen/","https://nvd.nist.gov/vuln/detail/CVE-2026-5821","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","https://research.cleantalk.org/cve-2026-5821","https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve"]}],"verification":[{"text":"更新後に同じ管理画面を開き直してバージョンを記録します。修正対象の系列・版と一致するかを照合し、サイト表示、ログイン、フォームや購入など普段使う主要な操作も確認してください。更新ボタンを押しただけでは完了としないでください。","kind":"procedure","sourceUrls":["https://wordpress.org/documentation/article/updating-wordpress/","https://wordpress.org/documentation/article/dashboard-updates-screen/"]}],"unknowns":["取り込んだ公開データには、修正済みと明記されたバージョン番号がありません。「修正されていない」と確定したわけではありません。下の問い合わせ文で、修正版の番号・提供場所・適用予定を確認できます。","AIによる全文翻訳は行っていません。公式の構造化データを決まったルールで日本語表示し、製品ごとの一般的な確認・更新手順を補足しています。本文だけに記された対象条件や例外は、併記した原文・根拠と照合してください。"],"supportRequest":"件名：CVE-2026-5821（Image Optimizer – Compress Images and Convert to WebP or AVIF）の影響と対応状況の確認\n\n利用中のサイト・機器・サービス：[記入してください]\n製品名・開発元：[記入してください]\n現在のバージョン・ビルド番号：[不明なら「不明」と記入]\n\nCVE-2026-5821について、次を教えてください。\n1. この環境は対象ですか。対象外の場合は、版・設定・機能などの判断理由を教えてください。\n2. 対象の場合、修正を含む版・パッケージ番号と、更新方法を教えてください。古い版に修正を取り込んでいる場合は、このCVEへの対応状況を教えてください。\n3. いつ対応できますか。再起動・停止時間・事前のバックアップや確認作業は必要ですか。\n4. すぐ更新できない場合、正式な回避策とその限界・副作用を教えてください。利用を続けてよい条件も知りたいです。\n5. 対応完了後、修正を確認できる版・設定・対応日時を連絡してください。\n\n確認している情報：https://zeijaku.ittrip.xyz/vulnerabilities/CVE-2026-5821","sources":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-5821","label":"NVDの原文"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-backup.php#L117","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/classes/image/image-meta.php#L97","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/tags/1.7.3/modules/backups/components/handle-backups-removing.php#L19","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-backup.php#L117","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/trunk/classes/image/image-meta.php#L97","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/browser/image-optimization/trunk/modules/backups/components/handle-backups-removing.php#L19","label":"security@wordfence.com"},{"url":"https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3557772%40image-optimization&new=3557772%40image-optimization&sfp_email=&sfph_mail=","label":"security@wordfence.com"},{"url":"https://research.cleantalk.org/cve-2026-5821","label":"security@wordfence.com"},{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/a1a00374-e9d6-46f9-a28c-cb7768505787?source=cve","label":"security@wordfence.com"},{"url":"https://www.first.org/cvss/v3.1/specification-document","label":"FIRST公式：CVSS 3.1の条件の定義"},{"url":"https://wordpress.org/documentation/article/plugins-screen/","label":"WordPress公式：プラグイン一覧"},{"url":"https://wordpress.org/documentation/article/site-health-screen/","label":"WordPress公式：サイトヘルスの情報"},{"url":"https://wordpress.org/documentation/article/updating-wordpress/","label":"WordPress公式：本体の更新"},{"url":"https://wordpress.org/documentation/article/dashboard-updates-screen/","label":"WordPress公式：更新画面"},{"url":"https://wordpress.org/documentation/article/manage-plugins/","label":"WordPress公式：プラグインの確認と更新"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-5821","label":"公式記録の識別番号"}],"glossary":[],"generationMethod":"rules","model":null,"generatedAt":null,"generatorVersion":"2026-10-23.3","ruleVersion":"2026-10-25.1","sourceFingerprint":"457bf5dcf260f028980b6f5c3dc2241be5350d551cf390977625a8a0133a3f36","sourceModifiedAt":"2026-10-28T01:16:55.603Z","verificationMethod":"structured_source_fields_and_rules","summaryEvidenceIds":[],"riskEvidenceIds":[],"evidence":[{"id":"E1","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-5821","sourceField":"/originalText","excerpt":"The Image Optimizer plugin for WordPress is vulnerable to arbitrary file deletion in versions up to and including 1.7.4. This is due to insufficient path validation in the Image_Backup::remove() function where backup file paths stored in post meta are used directly in file deletion operations without verifying they are within the uploads directory. The plugin stores backup file paths in the image_optimizer_metadata post meta field and trusts these paths completely when deleting backups on the delete_attachment hook. An authenticated attacker with Author-level access can edit the image_optimizer_metadata post meta on their own attachments via WordPress's Custom Fields interface, injecting arbitrary absolute file paths into the backups array. When the attacker subsequently deletes the attachment, the plugin calls File_System::delete() on each path without validation. This makes it possible for authenticated attackers, with Author-level access and above, to delete arbitrary files on the server within the web server's filesystem permissions, potentially leading to denial of service, data loss, or security degradation.","language":"und"},{"id":"E2","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-5821","sourceField":"/affected","excerpt":"[{\"product\":\"Image Optimizer – Compress Images and Convert to WebP or AVIF\",\"range\":\"<= 1.7.4\"}]","language":"und"},{"id":"E3","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-5821","sourceField":"/affectedDetails","excerpt":"[{\"vendor\":\"elemntor\",\"product\":\"Image Optimizer – Compress Images and Convert to WebP or AVIF\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"0\",\"lessThanOrEqual\":\"1.7.4\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]","language":"und"},{"id":"E4","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-5821","sourceField":"/recordId","excerpt":"CVE-2026-5821","language":"und"}],"automation":{"mode":"rules_only","aiEnabled":false,"enrichmentScheduled":false,"dataRefreshMode":"source_import_only","status":"pending","lastAttempt":null,"lastSuccess":null,"sourceCheckedAt":null,"errorCode":null}}}}