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.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

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 no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Symfony
  • Symfony

No data.

No data.

References
Link Providers
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-c2p3-7m5p-cv8x cve-icon
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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-07-14T18:45:03.458Z

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

No data.

cve-icon Redhat

No data.