CVE-2026-45305
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.68%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.68% probability · 52th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-1333
- Affected
- sensiolabs/symfony
- Source
- security-advisories@github.com
EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/symfony/symfony/commit/9749cd43c5e09b3735093623670b21b9d8a056cbPatch
- https://github.com/symfony/symfony/releases/tag/v5.4.52Product, Release Notes
- https://github.com/symfony/symfony/releases/tag/v6.4.40Product, Release Notes
- https://github.com/symfony/symfony/releases/tag/v7.4.12Product, Release Notes
- https://github.com/symfony/symfony/releases/tag/v8.0.12Product, Release Notes
- https://github.com/symfony/symfony/security/advisories/GHSA-9frc-8383-795mPatch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.