{"id":"CVE-2026-109413","revision":"bce82573900b4208b72e3c357c2bf835","records":[{"revision":"bce82573900b4208b72e3c357c2bf835","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-109413","aliases":[],"title":"Symfony: Unbounded Recursion in the YAML Inline Lexer Lets a Single Document Crash the Process","description":"In Symfony YAML prior to versions\u00A05.4.54,\u00A06.4.45,\u00A07.4.18, and\u00A08.1.6,\u00A0Yaml\\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\u00A0through v5.4.53, v6.0.0-BETA1 through\u00A0v6.4.44, v7.0.0-BETA1 through\u00A0v7.4.17, and v8.0.0-BETA1 through\u00A0v8.1.5.","state":0,"publishedAt":"2026-10-15T14:57:00.211+00:00","modifiedAt":"2026-10-15T18:06:55.183+00:00","affected":[{"ecosystem":"https://packagist.org/packages/symfony/yaml","name":"symfony/yaml","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"sensiolabs\",\n                    \"product\": \"symfony\",\n                    \"collectionURL\": \"https://packagist.org/packages/symfony/yaml\",\n                    \"packageName\": \"symfony/yaml\",\n                    \"repo\": \"https://github.com/symfony/yaml\",\n                    \"modules\": [\n                        \"Symfony\\\\\\\\Component\\\\\\\\Yaml\\\\\\\\Parser::lexInlineStructure()\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"lessThan\": \"v5.4.54\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"v6.0.0-BETA1\",\n                            \"lessThan\": \"v6.4.45\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"v7.0.0-BETA1\",\n                            \"lessThan\": \"v7.4.18\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"v8.0.0-BETA1\",\n                            \"lessThan\": \"v8.1.6\",\n                            \"versionType\": \"git\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":8.7,"severity":"HIGH"}],"references":["https://github.com/symfony/symfony/security/advisories/GHSA-2v3c-qxhr-7vpv","https://symfony.com/blog/cve-2026-109413-unbounded-recursion-in-the-yaml-inline-lexer-lets-a-single-document-crash-the-process","https://github.com/symfony/symfony/pull/65688"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-109413","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-109413","identifiers":["CVE-2026-109413"]},"retained":false,"historicalAffected":[]}],"coverage":[]}