| Name | CVE-2026-109413 |
| Description | 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. Any 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. This 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-6612-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| symfony (PTS) | bookworm, bookworm (security) | 5.4.53+dfsg-0+deb12u1 | vulnerable |
| trixie | 6.4.41+dfsg-0+deb13u1 | vulnerable | |
| trixie (security) | 6.4.49+dfsg-0+deb13u1 | fixed | |
| forky | 7.4.22+dfsg-1 | fixed | |
| sid | 7.4.23+dfsg-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| symfony | source | trixie | 6.4.49+dfsg-0+deb13u1 | DSA-6612-1 | ||
| symfony | source | (unstable) | 7.4.18+dfsg-1 |
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