{"answers":{"affected":"","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39838 exists.","fix":"No fix has been published for CVE-2026-39838 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-39838 is a medium-severity cross-site scripting vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage Extension, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-39838 and fix it if it is affected.\n\nWhat it is: CVE-2026-39838 is a medium-severity cross-site scripting vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage Extension, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39838 exists.\n\nAffected product: Wikimedia Foundation MediaWiki - ProofreadPage Extension. No package-level version data is available, so check the vendor advisory linked from the reference page.\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-2026-39838/ (Markdown: https://insights.sbomify.com/CVE-2026-39838/index.md)","id":"CVE-2026-39838","markdown":"https://insights.sbomify.com/CVE-2026-39838/index.md","name":"CVE-2026-39838","record":{"aliases":["GHSA-9jh3-xqmw-83x6"],"analysis":{"component_type":"cms_plugin","fix_type":"patch","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"MediaWiki ProofreadPage extension","requires_auth":"none","summary":"Attackers can inject malicious scripts via improperly sanitized CSS styles in the ProofreadPage extension, potentially compromising user sessions.","user_interaction":"not_required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"wikimedia-foundation","cpe":[],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage Extension allows XSS Targeting Non-Script Elements.\nThe issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":null,"headline":"ProofreadPage improperly sanitizes multiline styles using Sanitizer::checkCSS","id":"CVE-2026-39838","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"xss","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"Stored XSS through URLs in Cargo's map format","id":"CVE-2026-39839"},"packages":[],"prev":{"headline":"Stored XSS through the dynamic table format in Cargo","id":"CVE-2026-39837"},"products":["MediaWiki - ProofreadPage Extension"],"published":"2026-04-07","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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":"2026-04-08","vendors":["Wikimedia Foundation"]},"summary":"Attackers can inject malicious scripts via improperly sanitized CSS styles in the ProofreadPage extension, potentially compromising user sessions.","url":"https://insights.sbomify.com/CVE-2026-39838/"}