{"schema":"threatline.record/2","record":{"id":"CVE-2026-109413","aliases":["GHSA-2v3c-qxhr-7vpv"],"summary":"Symfony: Unbounded Recursion in the YAML Inline Lexer Lets a Single Document Crash the Process","details":"In Symfony YAML prior to versions 5.4.54, 6.4.45, 7.4.18, and 8.1.6, Yaml\\Parser::lexInlineStructure() recursed through lexInlineMapping() and lexInlineSequence() for every { and [ of an inline collection, without entering the nesting level that the rest of the parser bounds with maxNestingLevel. A document made of deeply nested inline collections, such as [[[[...]]]], exhausted the stack while it was being lexed: depending on the PHP version and its stack settings, the process crashed or the request ended with a fatal error.\n\n\n\nAny code parsing untrusted YAML is affected. That includes #[MapRequestPayload] when the Yaml component is installed and the endpoint does not restrict acceptFormat: a single unauthenticated request with a YAML content type is enough.\n\n\n\nThis issue affects symfony/yaml through v5.4.53, v6.0.0-BETA1 through v6.4.44, v7.0.0-BETA1 through v7.4.17, and v8.0.0-BETA1 through v8.1.5.","categories":["Frameworks"],"product":"symfony","vendor":"sensiolabs","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-109413","source_modified_at":"2026-10-15T18:06:55.183Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"symfony","vendor":"sensiolabs","versions":[{"status":"affected","version":"0","lessThan":"v5.4.54","versionType":"git"},{"status":"affected","version":"v6.0.0-BETA1","lessThan":"v6.4.45","versionType":"git"},{"status":"affected","version":"v7.0.0-BETA1","lessThan":"v7.4.18","versionType":"git"},{"status":"affected","version":"v8.0.0-BETA1","lessThan":"v8.1.6","versionType":"git"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":8.7,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00507,"percentile":0.42373,"score_date":"2026-10-23"},"published_at":"2026-10-15T14:57:00.211Z","modified_at":"2026-10-15T18:06:55.183Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-109413","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-15T18:06:55.183Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-109413","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/symfony/symfony/security/advisories/GHSA-2v3c-qxhr-7vpv","tags":["third-party-advisory"]},{"source":"CVE List","url":"https://symfony.com/blog/cve-2026-109413-unbounded-recursion-in-the-yaml-inline-lexer-lets-a-single-document-crash-the-process","tags":["vendor-advisory"]},{"source":"CVE List","url":"https://github.com/symfony/symfony/pull/65688","tags":["patch"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"yes","technical_impact":"partial","assessed_at":"2026-10-15T18:06:37.552332Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-15T18:06:55.183Z","content_hash":"12793152761b62037e78e306bb8395406c1aead00c1b72a54fa72260989abe63"}}