{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-34090 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-34090 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-34090 is a medium-severity vulnerability in Wikimedia Foundation CheckUser, published on 11 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-34090 and fix it if it is affected.\n\nWhat it is: CVE-2026-34090 is a medium-severity vulnerability in Wikimedia Foundation CheckUser, published on 11 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-34090 in the wild and no public exploit code.\n\nAffected product: Wikimedia Foundation CheckUser. 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-2026-34090/ (Markdown: https://insights.sbomify.com/CVE-2026-34090/index.md)","id":"CVE-2026-34090","markdown":"https://insights.sbomify.com/CVE-2026-34090/index.md","name":"CVE-2026-34090","record":{"aliases":["GHSA-cg3w-6fh3-65mw"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"Wikimedia CheckUser extension","requires_auth":"high_privilege","summary":"An attacker can view suppressed usernames, exposing sensitive user data in the Wikimedia CheckUser extension.","user_interaction":"required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"wikimedia-foundation","cpe":[{"product":"checkuser","vendor":"mediawiki"}],"cvss":{"score":4.8,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/R:U","version":"4.0"},"cwes":[{"id":"CWE-200","name":"Exposure of Sensitive Information to an Unauthorized Actor"}],"description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation CheckUser.\n\nThis issue affects CheckUser: from 1.45.0 before 1.45.2.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":null,"headline":"Suggested investigations: Handle suppressed usernames","id":"CVE-2026-34090","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"information_disclosure","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"User localization leaked by AbuseFilter + EventStream","id":"CVE-2026-34091"},"packages":[],"prev":{"headline":"Memory leak in Scribunto causes runJobs.php to run out of memory","id":"CVE-2026-34089"},"products":["CheckUser"],"published":"2026-05-11","related":[{"cvss_score":6.8,"headline":"Cross-site request forgery in n/a","id":"CVE-2015-2940","kev_date_added":null,"published":"2015-04-13"},{"cvss_score":6.5,"headline":"Information disclosure in n/a","id":"CVE-2019-18611","kev_date_added":null,"published":"2019-10-29"},{"cvss_score":5.3,"headline":"Information disclosure in n/a","id":"CVE-2019-16529","kev_date_added":null,"published":"2020-03-19"},{"cvss_score":1.3,"headline":"Special:GlobalContributions shows edits on wikis the viewer doesn't have access to","id":"CVE-2025-61658","kev_date_added":null,"published":"2026-02-03"},{"cvss_score":0,"headline":"Stored XSS through system messages in CheckUser","id":"CVE-2025-61648","kev_date_added":null,"published":"2026-02-03"},{"cvss_score":0,"headline":"i18n XSS through Special:CheckUser CheckUser helper","id":"CVE-2025-61651","kev_date_added":null,"published":"2026-02-03"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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":"2026-05-11","vendors":["Wikimedia Foundation"]},"summary":"An attacker can view suppressed usernames, exposing sensitive user data in the Wikimedia CheckUser extension.","url":"https://insights.sbomify.com/CVE-2026-34090/"}