CVE-2026-48784

MEDIUM5.1

Symfony: UrlGenerator Dot-Segment Encoding Skips Every Other Chained `../` or `./` → Generated URL Collapses Off-Route Under RFC 3986 Normalization

Published Jul 14, 2026

Modified Yesterday

Details

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.

References

WEB

https://github.com/symfony/symfony/commit/4b63c3a3f7af04ecd79c89a594b0b02a01990b1d

WEB

https://github.com/symfony/symfony/releases/tag/v5.4.53

WEB

https://github.com/symfony/symfony/releases/tag/v6.4.41

WEB

https://github.com/symfony/symfony/releases/tag/v7.4.13

WEB

https://github.com/symfony/symfony/security/advisories/GHSA-h5x3-xfc9-m39h

ADVISORY