{"answers":{"affected":"2 open source packages ship an affected version, including dompurify. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41240 exists.","fix":"Upgrade dompurify to 3.4.0 or later.","what":"CVE-2026-41240 is a medium-severity cross-site scripting vulnerability in cure53 DOMPurify, published on 23 Apr 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-2026-41240 and fix it if it is affected.\n\nWhat it is: CVE-2026-41240 is a medium-severity cross-site scripting vulnerability in cure53 DOMPurify, published on 23 Apr 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41240 exists.\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-2026-41240/ (Markdown: https://insights.sbomify.com/CVE-2026-41240/index.md)","id":"CVE-2026-41240","markdown":"https://insights.sbomify.com/CVE-2026-41240/index.md","name":"CVE-2026-41240","record":{"aliases":["CLEANSTART-2026-PO95463","CLEANSTART-2026-SE92910","DEBIAN-CVE-2026-41240","ECHO-a5a3-4e39-a94b","GHSA-h7mw-gpvr-xq4m","MINI-42pm-x8wv-jhvm","MINI-63v6-83mp-xjjf","MINI-94vc-xm3h-9f6j","MINI-9pcq-w43x-qmc2","MINI-ggq4-hpj5-ff67","MINI-hf94-3pxv-p44m","MINI-jj2w-g8c3-wp74","MINI-jwxq-j82w-c47f","MINI-mrjh-ffc3-43r7","MINI-qqjr-74cc-7wrw","MINI-vfv9-xwcw-p7hj","ROOT-APP-NPM-CVE-2026-41240","UBUNTU-CVE-2026-41240","openSUSE-SU-2026:10888-1"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":true,"product_category":"JavaScript HTML sanitizer","requires_auth":"none","summary":"DOMPurify fails to enforce FORBID_TAGS when function-based ADD_TAGS is used, allowing XSS via forbidden elements.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"dompurify","vendor":"cure53"}],"cvss":{"score":6,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"},{"id":"CWE-183","name":"Permissive List of Allowed Inputs"}],"description":"DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions prior to 3.4.0 have an inconsistency between FORBID_TAGS and FORBID_ATTR handling when function-based ADD_TAGS is used. Commit c361baa added an early exit for FORBID_ATTR at line 1214. The same fix was not applied to FORBID_TAGS. At line 1118-1123, when EXTRA_ELEMENT_HANDLING.tagCheck returns true, the short-circuit evaluation skips the FORBID_TAGS check entirely. This allows forbidden elements to survive sanitization with their attributes intact. Version 3.4.0 patches the issue.","ecosystems":["npm","openSUSE:Tumbleweed"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"DOMPurify: FORBID_TAGS bypassed by function-based ADD_TAGS predicate (asymmetry with FORBID_ATTR fix)","id":"CVE-2026-41240","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":3,"n_references":3,"next":{"headline":"pretalx: Stored cross-site scripting in organiser search typeahead","id":"CVE-2026-41241"},"packages":[{"ecosystem":"npm","fixed":["3.4.0"],"introduced":["0"],"last_affected":[],"package":"dompurify","purl":null,"source":"GHSA-h7mw-gpvr-xq4m"},{"ecosystem":"npm","fixed":["3.4.0"],"introduced":["0"],"last_affected":[],"package":"dompurify","purl":"pkg:npm/dompurify","source":"GHSA-h7mw-gpvr-xq4m"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["3.4.3-1.1"],"introduced":["0"],"last_affected":[],"package":"argocd-cli","purl":"pkg:rpm/opensuse/argocd-cli\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2026:10888-1"}],"prev":{"headline":"DOMPurify has a SAFE_FOR_TEMPLATES bypass in RETURN_DOM mode","id":"CVE-2026-41239"},"products":["DOMPurify"],"published":"2026-04-23","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":"CC BY 4.0","name":"SUSE","prefix":"openSUSE"},{"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":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-04-23","vendors":["cure53"]},"summary":"DOMPurify fails to enforce FORBID_TAGS when function-based ADD_TAGS is used, allowing XSS via forbidden elements.","url":"https://insights.sbomify.com/CVE-2026-41240/"}