{"id":"CVE-2026-33347","summary":"league/commonmark has an embed extension allowed_domains bypass","details":"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.","aliases":["GHSA-hh8v-hgvp-g3f5"],"modified":"2026-04-10T04:17:07.064848Z","published":"2026-03-24T19:26:23.872Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33347.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-185","CWE-79","CWE-918"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33347.json"},{"type":"FIX","url":"https://github.com/thephpleague/commonmark/commit/59fb075d2101740c337c7216e3f32b36c204218b"},{"type":"WEB","url":"https://github.com/thephpleague/commonmark/releases/tag/2.8.2"},{"type":"ADVISORY","url":"https://github.com/thephpleague/commonmark/security/advisories/GHSA-hh8v-hgvp-g3f5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33347"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/thephpleague/commonmark","events":[{"introduced":"32a49eb2b38fe5e5c417ab748a45d0beaab97955"},{"fixed":"59fb075d2101740c337c7216e3f32b36c204218b"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"2.3.0"},{"fixed":"2.8.2"}]}}],"versions":["2.3.0","2.4.0","2.5.0","2.6.0","2.7.0","2.8.0","2.8.1"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-33347.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N"}]}