Vulnerability · Published Jul 14, 2026 · Assigned by GitHub_M

CVE-2026-48784Symfony: UrlGenerator Dot-Segment Encoding Skips Every Other Chained `../` or `./` → Generated URL Collapses Off-Route Under RFC 3986 Normalization

Medium 5.1

In plain English

A medium-severity open redirect in routing from symfony. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.1Medium
Exploit odds (30 days)0.3%top 71.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12symfony5.4.53+dfsg-0+deb12u1DEBIAN-CVE-2026-48784
Debian:13symfony6.4.41+dfsg-0+deb13u1DEBIAN-CVE-2026-48784
Debian:14symfony7.4.13+dfsg-1DEBIAN-CVE-2026-48784
Packagistsymfony/routing5.4.53GHSA-h5x3-xfc9-m39h
Packagistsymfony/routing6.4.41GHSA-h5x3-xfc9-m39h
Packagistsymfony/routing7.4.13GHSA-h5x3-xfc9-m39h
Packagistsymfony/routing8.0.13GHSA-h5x3-xfc9-m39h
Packagistsymfony/symfony8.0.13GHSA-h5x3-xfc9-m39h
Packagistsymfony/symfony5.4.53GHSA-h5x3-xfc9-m39h
Packagistsymfony/symfony6.4.41GHSA-h5x3-xfc9-m39h
Packagistsymfony/symfony7.4.13GHSA-h5x3-xfc9-m39h
Ubuntu:25.10symfonyno fix listedUBUNTU-CVE-2026-48784
Ubuntu:26.04:LTSsymfonyno fix listedUBUNTU-CVE-2026-48784
Ubuntu:26.10symfonyno fix listedUBUNTU-CVE-2026-48784

Affected products (as reported)

VendorProductVersions
symfony symfony < 5.4.53>= 6.0.0-BETA1, < 6.4.41>= 7.0.0-BETA1, < 7.4.13>= 8.0.0-BETA1, < 8.0.13
symfony routing < 5.4.53>= 6.0.0-BETA1, < 6.4.41>= 7.0.0-BETA1, < 7.4.13>= 8.0.0-BETA1, < 8.0.13

Weakness: CWE-172, CWE-601 · Vector: 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

References