high8.6
CVE-2026-48736
Symfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient
Impact
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
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | symfony/http-client | >= 5.4.0, < 5.4.53 | 5.4.53 |
| composer | symfony/http-foundation | >= 6.4.0, < 6.4.41 | 6.4.41 |
| composer | symfony/symfony | >= 5.4.0, < 5.4.53 | 5.4.53 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Sensiolabs | Symfony | from 5.4.0 before 5.4.43 from 6.4.0 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-38cx-cq6f-5755
- https://github.com/symfony/symfony/security/advisories/GHSA-38cx-cq6f-5755
- https://github.com/symfony/symfony/commit/82765368cf74177c36613575182f168a2eb765b2
- https://github.com/symfony/symfony/commit/85b831555be8ea1f43bf01078afe87bc4c92f65e
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-client/CVE-2026-48736.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-foundation/CVE-2026-48736.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-48736.yaml
- https://symfony.com/cve-2026-48736
- 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