CVE-2026-45133 Details
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.
A denial-of-service vulnerability has been identified in the Symfony YAML parser component. Prior to versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12, the parser could be exposed to attacker-controlled input that, when deeply nested mappings or sequences were introduced, caused both block-level and inline parsers to recurse without a depth limit. This unbounded recursion led to a stack exhaustion, crashing the PHP worker. The issue has been reported by Pietro Tirenna (Shielder) and fixed by Nicolas Grekas.
Users can update to Symfony versions 5.4.52, 6.4.40, 7.4.12, or 8.0.12 to address this vulnerability. The patch for this issue is available in the Symfony GitHub repository.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 15, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/symfony/symfony/releases/tag/v5.4.52 | [email protected] | ProductRelease Notes |
| https://github.com/symfony/symfony/releases/tag/v6.4.40 | [email protected] | ProductRelease Notes |
| https://github.com/symfony/symfony/releases/tag/v7.4.12 | [email protected] | ProductRelease Notes |
| https://github.com/symfony/symfony/releases/tag/v8.0.12 | [email protected] | ProductRelease Notes |
| https://github.com/symfony/symfony/security/advisories/GHSA-c2p3-7m5p-cv8x | [email protected] | PatchVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1333 | Inefficient Regular Expression Complexity | [email protected] |
| CWE-674 | Uncontrolled Recursion | [email protected] |
| CWE-776 | Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| sensiolabs symfony | < 5.4.52 >= 6.0.0, < 6.4.40 >= 7.0.0, < 7.4.12 >= 8.0.0, < 8.0.12 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 15, 2026 | Initial Analysis | [email protected] |
| Jul 15, 2026 | CVE Modified | CISA-ADP |
| Jul 14, 2026 | New CVE Received | [email protected] |