CVE catalog
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
- Severity
- Medium · CVSS 6.3
- Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.25% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | php-league-commonmark | sid | 2.10.4-1 | fixed |
| Debian | php-league-commonmark | forky | 2.10.4-1 | fixed |
| Debian | php-league-commonmark | trixie | 2.7.0-1+deb13u1 | fixed |
| Debian | php-league-commonmark | bookworm | 2.3.9-1+deb12u1 | fixed |
| Composer | league/commonmark | Not reported | 2.8.2 | fixed |
| Cpe | php-league-commonmark | Not reported | Not reported | vulnerable |
| Cpe | php-league-commonmark | Not reported | 2.4.2-2ubuntu0.1~esm1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | php-league-commonmark | source | sid | 2.8.2-1 | not yet assigned | Not reported | Not reported |
| Debian | php-league-commonmark | source | forky | 2.8.2-1 | not yet assigned | Not reported | Not reported |
| Debian | php-league-commonmark | source | trixie | 2.7.0-1+deb13u1 | not yet assigned | Not reported | Not reported |
| Debian | php-league-commonmark | source | bookworm | 2.3.9-1+deb12u1 | not yet assigned | Not reported | Not reported |
| Composer | league/commonmark | composer | Not reported | 2.8.2 | Not reported | Not reported | Not reported |
| Cpe | php-league-commonmark | cpe | Not reported | 2.4.2-2ubuntu0.1~esm1 | Not reported | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [php-league-commonmark]Fixed
Details (2)
2.3.9-1+deb12u1· all · bookwormFixed · Fixed:
2.3.9-1+deb12u1nvd · php-league-commonmark · debian · bookworm; nvd · php-league-commonmark · debian · 12
2.3.9-1+deb12u1· all · bookwormFixed · Fixed:
2.3.9-1+deb12u1nvd · php-league-commonmark · debian · bookworm; nvd · php-league-commonmark · debian · 12
[Debian 13 (Trixie)]
- [php-league-commonmark]Fixed
Details (2)
2.7.0-1+deb13u1· all · trixieFixed · Fixed:
2.7.0-1+deb13u1nvd · php-league-commonmark · debian · 13
2.7.0-1+deb13u1· all · trixieFixed · Fixed:
2.7.0-1+deb13u1nvd · php-league-commonmark · debian · 13
Observed:
References
- [https://github.com/advisories/GHSA-hh8v-hgvp-g3f5]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-33347]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-33347]
- [https://security-tracker.debian.org/tracker/CVE-2026-33347]
- [https://ubuntu.com/security/notices/USN-8194-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-1001.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Ubuntu Security Notices (USN)]