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, Symfony\Component\Yaml\Parser::cleanup() used regular expressions with overlapping quantifiers for YAML directive, comment, and document marker cleanup, allowing crafted input to make parsing hang for an arbitrarily long time. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

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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-9frc-8383-795m Symfony's YAML Parser has a ReDoS via Catastrophic Backtracking in Parser::cleanup() Regex
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 27 Jul 2026 15:30:00 +0000

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

Wed, 15 Jul 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', '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, Symfony\Component\Yaml\Parser::cleanup() used regular expressions with overlapping quantifiers for YAML directive, comment, and document marker cleanup, allowing crafted input to make parsing hang for an arbitrarily long time. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.
Title Symfony: YAML Parser ReDoS via Catastrophic Backtracking in Parser::cleanup() Regex
Weaknesses CWE-1333
References
Metrics cvssV4_0

{'score': 8.7, '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-15T14:03:58.116Z

Reserved: 2026-05-11T20:14:43.202Z

Link: CVE-2026-45305

cve-icon Vulnrichment

Updated: 2026-07-15T14:03:54.863Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-27T14:58:51Z

Weaknesses