{"id":"CVE-2026-40470","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-40470","generatedAt":"2026-10-28T00:52:47.164Z","title":"A critical XSS vulnerability affected hackage-server and hackage.haskell.org.","description":"A critical XSS vulnerability affected hackage-server and\nhackage.haskell.org.  HTML and JavaScript files provided in source\npackages or via the documentation upload facility were served\nas-is on the main hackage.haskell.org domain.  As a consequence,\nwhen a user with latent HTTP credentials browses to the package\npages or documentation uploaded by a malicious package maintainer,\ntheir session can be hijacked to upload packages or\ndocumentation, amend maintainers or other package metadata, or\nperform any other action the user is authorised to do.","published":"2026-04-23T16:16:26.000Z","lastModified":"2026-06-17T10:45:20.000Z","status":"Awaiting Analysis","sourceIdentifier":"74b3a70d-cca6-4d34-9789-e83b222ae3be","cvss":{"version":"3.1","score":9.9,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L"},"cwe":["CWE-79"],"affected":[],"epss":{"score":0.00309,"percentile":0.23534,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://osv.dev/vulnerability/HSEC-2024-0004","source":"74b3a70d-cca6-4d34-9789-e83b222ae3be"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-40470","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}