{"id":"CVE-2026-109391","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-109391","summary":"Square Squash through commit e73f280 Unauthenticated YAML Deserialization via Symbolication API","details":"Square Squash through commit e73f280 contains an insecure deserialization vulnerability that allows unauthenticated attackers to store crafted YAML via the POST /api/1.0/symbolication endpoint. When occurrences referencing the attacker-controlled symbolication UUID are symbolicated, the stored values are passed to YAML.load with SafeYAML in unsafe mode, enabling arbitrary Ruby object deserialization and potential code execution.","published":"2026-10-12T15:16:39.257Z","modified":"2026-10-13T02:47:12.446285293Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109391.json"},{"type":"PACKAGE","url":"https://github.com/SquareSquash/web"},{"type":"ARTICLE","url":"https://github.com/SquareSquash/web/blob/e73f2805f9eb30780a5c213b001f0f4255660fbf/app/controllers/api/v1_controller.rb"},{"type":"ARTICLE","url":"https://github.com/SquareSquash/web/blob/e73f2805f9eb30780a5c213b001f0f4255660fbf/app/models/symbolication.rb"},{"type":"ARTICLE","url":"https://github.com/SquareSquash/web/blob/e73f2805f9eb30780a5c213b001f0f4255660fbf/config/preinitializers/safe_yaml.rb"},{"type":"ARTICLE","url":"https://github.com/SquareSquash/web/blob/e73f2805f9eb30780a5c213b001f0f4255660fbf/lib/workers/symbolication_creator.rb"},{"type":"EVIDENCE","url":"https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/HJ87QX5ifg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-109391"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/square-squash-through-commit-e73f280-unauthenticated-yaml-deserialization-via-symbolication-api"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-13T02:47:12.446285293Z"}}