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Vulnerability · Published Jul 14, 2026 · Assigned by GitHub_M

CVE-2026-48736Symfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient

Medium 6.9

In plain English

A medium-severity server-side request forgery in http-client from symfony. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.9Medium
Exploit odds (30 days)0.6%top 52.6% 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. From 5.4.0 to 5.4.53, 6.4.41, 7.4.13, and 8.0.13, NoPrivateNetworkHttpClient and IpUtils::PRIVATE_SUBNETS omitted IPv6 transition prefixes such as 6to4, NAT64, Teredo, and IPv4-compatible IPv6, allowing attacker-supplied URLs to represent private IPv4 targets in forms that IpUtils::isPrivateIp() did not block. 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-2026-48736
Debian:13symfony6.4.41+dfsg-0+deb13u1DEBIAN-CVE-2026-48736
Debian:14symfony7.4.13+dfsg-1DEBIAN-CVE-2026-48736
Packagistsymfony/http-client5.4.53GHSA-38cx-cq6f-5755
Packagistsymfony/http-foundation6.4.41GHSA-38cx-cq6f-5755
Packagistsymfony/http-foundation7.4.13GHSA-38cx-cq6f-5755
Packagistsymfony/http-foundation8.0.13GHSA-38cx-cq6f-5755
Packagistsymfony/symfony8.0.13GHSA-38cx-cq6f-5755
Packagistsymfony/symfony5.4.53GHSA-38cx-cq6f-5755
Packagistsymfony/symfony6.4.41GHSA-38cx-cq6f-5755
Packagistsymfony/symfony7.4.13GHSA-38cx-cq6f-5755
Ubuntu:25.10symfonyno fix listedUBUNTU-CVE-2026-48736
Ubuntu:26.04:LTSsymfonyno fix listedUBUNTU-CVE-2026-48736
Ubuntu:26.10symfonyno fix listedUBUNTU-CVE-2026-48736

Affected products (as reported)

VendorProductVersions
symfony symfony >= 5.4.0, < 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 http-client >= 5.4.0, < 5.4.53
symfony http-foundation >= 6.0.0-BETA1, < 6.4.41>= 7.0.0-BETA1, < 7.4.13>= 8.0.0-BETA1, < 8.0.13

Weakness: CWE-184, CWE-918 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N

References