CVE-2026-33347

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Source
https://cve.org/CVERecord?id=CVE-2026-33347
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33347.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-33347
Aliases
Downstream
Published
2026-03-24T19:26:23Z
Modified
2026-10-21T02:56:49Z
Severity
  • 6.3 (Medium) CVSS_V4 - 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 CVSS Calculator
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.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-185",
        "CWE-79",
        "CWE-918"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33347.json"
}
References

Affected packages

Git / github.com/thephpleague/commonmark

Affected ranges

Type
GIT
Repo
https://github.com/thephpleague/commonmark
Events
Introduced
32a49eb2b38fe5e5c417ab748a45d0beaab97955
Fixed
59fb075d2101740c337c7216e3f32b36c204218b
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "2.3.0"
                },
                {
                    "fixed":  "2.8.2"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "59fb075d2101740c337c7216e3f32b36c204218b"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "2.8.2",
            "range":  [
                {
                    "fixed":  "59fb075d2101740c337c7216e3f32b36c204218b"
                }
            ],
            "source":  "REFERENCES_TAG"
        },
        {
            "cpe":  "cpe:2.3:a:thephpleague:commonmark:*:*:*:*:*:*:*:*",
            "range":  [
                {
                    "introduced":  "2.3.0"
                },
                {
                    "fixed":  "2.8.2"
                }
            ],
            "source":  "CPE_RANGE"
        }
    ]
}

Affected versions

2.*
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/cve-osv-conversion/osv-output/CVE-2026-33347.json"