CVE-2026-45066CWE-184CWE-436

Symfony: HtmlSanitizer allowLinkHosts() / allowMediaHosts() Bypass via URL-Parser Differentials and <area> Misclassification

Low · published July 14, 2026

CVSS v4.0
2.3
EPSS
0%
Percentile
26.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
2.3 · LOW
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
EPSS
0.00338 · 26.0th percentile
Weaknesses
CWE-184 · Incomplete List of Disallowed Inputs; CWE-436 · Interpretation Conflict
Published
2026-07-14T17:53Z
EPSS history
Timeline
  • 14 JUL 17:53Z
    Symfony: HtmlSanitizer allowLinkHosts() / allowMediaHosts() Bypass via URL-Parser Differentials and <area> Misclassification
    cvelistv5