Vulnerability in Sensiolabs Symfony

CVE-2026-45066

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowlist URLs through allowLinkHosts() or allowMediaHosts() because UrlSanitizer::parse() follows RFC 3986 while browsers follow WHATWG URL parsing, and because <area href> is checked against the media policy rather than the link policy. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.

EPSS: 0.003 (26.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-45066?
CVE-2026-45066 is a medium-severity vulnerability in Sensiolabs Symfony, classified under Incomplete List of Disallowed Inputs. CVSS score: 6.1/10. Published 2026-07-14.
How severe is CVE-2026-45066?
Medium severity. CVSS v3 base score is 6.1 out of 10.