XSS in Thephpleague Commonmark

CVE-2026-33347

league/commonmark is a PHP Markdown parser. From version 2.3.0 to before version 2.8.2, the DomainFilteringAdapter in the Embed extension is vulnerable to an allowlist bypass due to a missing hostname boundary assertion in the domain-match…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (3.1th percentile) — read the EPSS interpretation.

Affected products

Thephpleague Commonmark — versions >= 2.3.0, < 2.8.2

Weakness classification (CWE)

References

https://github.com/thephpleague/commonmark/security/advisories/GHSA-hh8v-hgvp-g3f5 (x_refsource_CONFIRM)
https://github.com/thephpleague/commonmark/commit/59fb075d2101740c337c7216e3f32b36c204218b (x_refsource_MISC)
https://github.com/thephpleague/commonmark/releases/tag/2.8.2 (x_refsource_MISC)