medium6.1
CVE-2026-48784
Symfony: UrlGenerator Dot-Segment Encoding Skips Every Other Chained `../` or `./` → Generated URL Collapses Off-Route Under RFC 3986 Normalization
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | symfony/routing | < 5.4.53 | 5.4.53 |
| composer | symfony/symfony | < 5.4.53 | 5.4.53 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Sensiolabs | Symfony | before 5.4.53 from 6.0.0 before 6.4.41 from 7.0.0 before 7.4.13 from 8.0.0 before 8.0.13 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-h5x3-xfc9-m39h
- https://github.com/symfony/symfony/security/advisories/GHSA-h5x3-xfc9-m39h
- https://github.com/symfony/symfony/commit/4b63c3a3f7af04ecd79c89a594b0b02a01990b1d
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/routing/CVE-2026-48784.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-48784.yaml
- https://symfony.com/cve-2026-48784
- https://github.com/symfony/symfony/releases/tag/v5.4.53
- https://github.com/symfony/symfony/releases/tag/v6.4.41
- https://github.com/symfony/symfony/releases/tag/v7.4.13