CVSS 4.0
6.3 mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:NCVE-2026-33347
Medium (6.3) in thephpleague commonmark. EPSS 0.2% chance of exploitation in the next 30 days.
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-matching regex. An attacker-controlled domain like youtube.com.evil passes the allowlist check when youtube.com is an allowed domain. This issue has been patched in version 2.8.2.
Severity
CVSS 3.1
6.1 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 16% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-79, CWE-185, CWE-918
- Published
- Modified
- Record from
- the NVD, synced
Affected
- thephpleague:commonmark