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.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Symfony
  • Symfony
  • Yaml

No data.

No data.

References
Link Providers
https://github.com/symfony/symfony/commit/9749cd43c5e09b3735093623670b21b9d8a056cb cve-icon
https://github.com/symfony/symfony/releases/tag/v5.4.52 cve-icon
https://github.com/symfony/symfony/releases/tag/v6.4.40 cve-icon
https://github.com/symfony/symfony/releases/tag/v7.4.12 cve-icon
https://github.com/symfony/symfony/releases/tag/v8.0.12 cve-icon
https://github.com/symfony/symfony/security/advisories/GHSA-9frc-8383-795m cve-icon
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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-07-14T18:50:14.830Z

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

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