{"answers":{"affected":"2 open source packages ship an affected version, including dompurify. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-65903 in the wild and no public exploit code.","fix":"Upgrade dompurify to 3.4.0 or later.","what":"CVE-2026-65903 is a medium-severity vulnerability in cure53 DOMPurify, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-65903 and fix it if it is affected.\n\nWhat it is: CVE-2026-65903 is a medium-severity vulnerability in cure53 DOMPurify, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-65903 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- dompurify (npm): affected all versions; fixed in 3.4.0\n- dompurify (npm): affected all versions; fixed in 3.4.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-65903/ (Markdown: https://insights.sbomify.com/CVE-2026-65903/index.md)","id":"CVE-2026-65903","markdown":"https://insights.sbomify.com/CVE-2026-65903/index.md","name":"CVE-2026-65903","record":{"aliases":["CLEANSTART-2026-BG16749","CLSA-2026-1784596278","CLSA-2026-1784596303","DEBIAN-CVE-2026-65903","ECHO-c3eb-b997-34cf","GHSA-39q2-94rc-95cp","MINI-37xj-25wh-7wvm","MINI-6648-g9jp-49qr","MINI-686v-p2q2-6jhc","MINI-78h6-9mv2-f3cq","MINI-857x-34p7-5j64","MINI-9wch-cw6w-gx8x","MINI-f67j-6hqh-gfgj","MINI-gh5h-3gvr-cf97","MINI-v3m4-4p97-62qx","MINI-vhp3-w6pw-393q","MINI-wm7h-vppp-gw4x","ROOT-APP-NPM-CVE-2026-65903","ROOT-APP-NPM-GHSA-39q2-94rc-95cp","UBUNTU-CVE-2026-65903"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"JavaScript sanitization library","requires_auth":"none","summary":"Attackers can bypass DOMPurify's FORBID_TAGS restrictions by using ADD_TAGS, allowing forbidden HTML tags to remain in sanitized output.","user_interaction":"required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[{"product":"dompurify","vendor":"cure53"}],"cvss":{"score":5.1,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-697","name":"Incorrect Comparison"}],"description":"DOMPurify before 3.4.0 contains a logic error in the ADD_TAGS function where short-circuit evaluation allows forbidden tags to bypass FORBID_TAGS restrictions. Attackers can craft input containing tags listed in FORBID_TAGS that are also added via ADD_TAGS function, causing them to be retained in sanitized output.","ecosystems":["npm"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"DOMPurify before 3.4.0 ADD_TAGS Function Bypasses FORBID_TAGS","id":"CVE-2026-65903","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"security_feature_bypass","year":"2026"},"n_packages":2,"n_references":2,"next":{"headline":"DOMPurify through 3.3.3 Cross-Site Scripting via IN_PLACE mode","id":"CVE-2026-65904"},"packages":[{"ecosystem":"npm","fixed":["3.4.0"],"introduced":["0"],"last_affected":[],"package":"dompurify","purl":null,"source":"GHSA-39q2-94rc-95cp"},{"ecosystem":"npm","fixed":["3.4.0"],"introduced":["0"],"last_affected":[],"package":"dompurify","purl":"pkg:npm/dompurify","source":"GHSA-39q2-94rc-95cp"}],"prev":{"headline":"DOMPurify before 3.4.7 Hook Mutation Pollution via allowedTags","id":"CVE-2026-65902"},"products":["DOMPurify"],"published":"2026-07-23","related":[{"cvss_score":10,"headline":"DOMPurify nesting-based mXSS","id":"CVE-2024-47875","kev_date_added":null,"published":"2024-10-11"},{"cvss_score":9.1,"headline":"DOMPurify vulnerable to tampering by prototype polution","id":"CVE-2024-48910","kev_date_added":null,"published":"2024-10-31"},{"cvss_score":8.2,"headline":"DOMPurify XSS via `selectedcontent` re-clone","id":"CVE-2026-47423","kev_date_added":null,"published":"2026-07-14"},{"cvss_score":7.3,"headline":"Tampering by prototype polution in DOMPurify","id":"CVE-2024-45801","kev_date_added":null,"published":"2024-09-16"},{"cvss_score":6.3,"headline":"DOMPurify IN_PLACE Sanitization Bypass via Attached Shadow Root Inside \u003ctemplate\u003e.content","id":"CVE-2026-49978","kev_date_added":null,"published":"2026-07-14"},{"cvss_score":6.1,"headline":"DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks","id":"CVE-2026-49458","kev_date_added":null,"published":"2026-07-14"},{"cvss_score":6.1,"headline":"DOMPurify: IN_PLACE mode preserves attributes of a clobbered root element, allowing XSS via attacker-controlled root DOM","id":"CVE-2026-49459","kev_date_added":null,"published":"2026-07-14"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-23","vendors":["cure53"]},"summary":"Attackers can bypass DOMPurify's FORBID_TAGS restrictions by using ADD_TAGS, allowing forbidden HTML tags to remain in sanitized output.","url":"https://insights.sbomify.com/CVE-2026-65903/"}