SSRF in Sensiolabs Symfony

CVE-2026-48736

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.

EPSS: 0.006 (44.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-48736?
CVE-2026-48736 is a high-severity vulnerability in Sensiolabs Symfony, classified under Incomplete List of Disallowed Inputs. CVSS score: 8.6/10. Published 2026-07-14.
How severe is CVE-2026-48736?
High severity. CVSS v3 base score is 8.6 out of 10.