[MEDIUM] league/commonmark has an embed extension allowed_domains bypass

PKSA-21fb-n1x5-5nf7 CVE-2026-33347 GHSA-hh8v-hgvp-g3f5

Affected version: >=2.3.0,<=2.8.1

Reported by:
GitHub

[MEDIUM] CommonMark has DisallowedRawHtml extension bypass via whitespace in HTML tag names

PKSA-2cx9-ynrq-qdk3 CVE-2026-30838 GHSA-4v6x-c7xx-hw9f

Affected version: >=2.0.0,<=2.8.0

Reported by:
GitHub

[MEDIUM] league/commonmark contains a XSS vulnerability in Attributes extension

PKSA-rqc2-tcc6-nc79 CVE-2025-46734 GHSA-3527-qv2q-pfvx

Affected version: >=1.5.0,<2.7.0

Reported by:
GitHub

[HIGH] league/commonmark's quadratic complexity bugs may lead to a denial of service

PKSA-fndg-qryc-dyc9 GHSA-c2pc-g5qf-rfrf

Affected version: <2.6.0

Reported by:
GitHub

[MEDIUM] XSS vulnerability with double-encoded entities

PKSA-nyyp-2pk1-frkz CVE-2019-10010 GHSA-3v43-877x-qgmq

Affected version: <0.18.3

Reported by:
GitHub, FriendsOfPHP/security-advisories

[MEDIUM] XSS vulnerability with unsafe link protocols

PKSA-g6p7-7rfc-zbp2 CVE-2018-20583 GHSA-qx76-c53f-5c7q

Affected version: >=0.15.6,<0.18.1

Reported by:
GitHub, FriendsOfPHP/security-advisories