Description
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.53, 6.4.41, 7.4.13, and 8.0.13, UrlGenerator::doGenerate() used strtr() dot-segment encoding that skipped every other chained ../ or ./ segment, allowing attacker-controlled route parameters to generate URLs that collapse to a different path under RFC 3986 normalization. This issue is fixed in versions 5.4.53, 6.4.41, 7.4.13, and 8.0.13.
Affected products
sensiolabs: symfony
References5
- github.com/symfony/symfony/security/advisories/GHSA-h5x3-xfc9-m… PatchVendor Advisory
- github.com/symfony/symfony/commit/4b63c3a3f7af04ecd79c89a594b0b… Patch
- github.com/symfony/symfony/releases/tag/v5.4.53 ProductRelease Notes
- github.com/symfony/symfony/releases/tag/v6.4.41 ProductRelease Notes
- github.com/symfony/symfony/releases/tag/v7.4.13 ProductRelease Notes
Metrics
- CVSS 3.1
-
6.1
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 4.0
-
5.1
MEDIUM
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 29 · as of 15 November 2026
- CWE
- CWE-172CWE-601
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.