CVE-2026-71478

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Source
https://cve.org/CVERecord?id=CVE-2026-71478
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-71478.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-71478
Aliases
Downstream
CLSA (3)
DEBIAN (1)
UBUNTU (1)
Published
2026-08-06T20:30:32Z
Modified
2026-10-21T02:59:09Z
Severity
  • 6.1 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
Summary
league/commonmark: AttributesExtension href/src unsafe-link filter bypass via embedded control bytes
Details

league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a javascript: URL that browsers discard before parsing the scheme, causing the browser to still execute the script even when the unsafe-link filter is enabled. This issue is fixed in 2.9.0.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-692",
        "CWE-79",
        "CWE-86"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71478.json"
}
References

Affected packages

Git / github.com/thephpleague/commonmark

Affected ranges

Type
GIT
Repo
https://github.com/thephpleague/commonmark
Events
Introduced
fc33ca12575e98e57cdce7d5f38b2ca5335714b3
Fixed
493a5aa7d65754b73846006eaff9c2c4431a8e2c
Fixed
5703d83ba3da3b2e356a5fedc848ed6d8ffb6529
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "1.5.0"
                },
                {
                    "last_affected":  "2.8.3"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "493a5aa7d65754b73846006eaff9c2c4431a8e2c"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "2.9.0",
            "range":  [
                {
                    "fixed":  "5703d83ba3da3b2e356a5fedc848ed6d8ffb6529"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-71478.json"