{"id":"CVE-2026-23991","aliases":["GHSA-846p-jg2w-w324","GO-2026-4348"],"url":"https://o3.security/vulnerability/CVE-2026-23991","summary":"go-tuf affected by client DoS via malformed server response","details":"# Security Disclosure: Client DoS via malformed server response\n\n## Summary\n\nIf the TUF repository (or any of its mirrors) returns invalid TUF metadata JSON (valid JSON but not well formed TUF metadata), the client will panic _during parsing_, causing a DoS. The panic happens before any signature is validated. This means that a compromised repository/mirror/cache can DoS clients without having access to any signing key.\n\n## Impact \n\nClient crashes upon receiving and parsing malformed TUF metadata. This can cause long running services to enter an restart/crash loop.\n\n## Workarounds\n\nNone currently. \n\n## Affected code\n\nThe `metadata.checkType` function did not properly type assert the (untrusted) input causing it to panic on malformed data.","published":"2026-01-22T02:16:37.294Z","modified":"2026-08-12T03:51:39.758481582Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.0054,"percentile":0.42961,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/theupdateframework/go-tuf/v2","fixedVersion":"2.3.1"}],"fix":{"url":"https://github.com/theupdateframework/go-tuf/commit/73345ab6b0eb7e59d525dac17a428f043074cef6","label":"theupdateframework/go-tuf@73345ab"},"references":[{"type":"WEB","url":"https://github.com/theupdateframework/go-tuf/releases/tag/v2.3.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23991.json"},{"type":"ADVISORY","url":"https://github.com/theupdateframework/go-tuf/security/advisories/GHSA-846p-jg2w-w324"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23991"},{"type":"FIX","url":"https://github.com/theupdateframework/go-tuf/commit/73345ab6b0eb7e59d525dac17a428f043074cef6"},{"type":"PACKAGE","url":"https://github.com/theupdateframework/go-tuf"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:39.758481582Z"}}