Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, when the parser is exposed to attacker-controlled input, deeply nested mappings or sequences cause both the block-level (Parser::parseBlock()) and inline (Inline::parseSequence() / Inline::parseMapping()) parsers to recurse without a depth limit. A crafted document exhausts the PHP stack and crashes the worker. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.
Advisories
Source ID Title
Debian DSA Debian DSA DSA-6312-1 symfony security update
Debian DSA Debian DSA DSA-6317-1 symfony security update
Github GHSA Github GHSA GHSA-c2p3-7m5p-cv8x Symfony hardened the parser when handling untrusted input
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 15 Jul 2026 18:15:00 +0000

Type Values Removed Values Added
First Time appeared Symfony
Symfony symfony
Vendors & Products Symfony
Symfony symfony

Wed, 15 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 14 Jul 2026 19:00:00 +0000

Type Values Removed Values Added
Description Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, when the parser is exposed to attacker-controlled input, deeply nested mappings or sequences cause both the block-level (Parser::parseBlock()) and inline (Inline::parseSequence() / Inline::parseMapping()) parsers to recurse without a depth limit. A crafted document exhausts the PHP stack and crashes the worker. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.
Title Symfony: [Yaml] Harden the parser when handling untrusted input
Weaknesses CWE-1333
CWE-674
CWE-776
References
Metrics cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-15T13:25:32.835Z

Reserved: 2026-05-08T20:08:17.209Z

Link: CVE-2026-45133

cve-icon Vulnrichment

Updated: 2026-07-15T13:25:26.103Z

cve-icon NVD

Status : Analyzed

Published: 2026-07-14T19:17:06.913

Modified: 2026-07-15T14:54:50.237

Link: CVE-2026-45133

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-31T05:45:03Z

Weaknesses