CVE-2026-4923

When using multiple wildcards, combined with at least one parameter, a regular expression can be generated that is vulnerable to ReDoS. This backtracking vulnerability requires the second wildcard to be somewhere other than the end of the path.

Unsafe examples:

/*foo-*bar-:baz /*a-:b-*c-:d /x/*a-:b/*c/y

Safe examples:

/*foo-:bar /*foo-:bar-*baz

Patches:

Upgrade to version 8.4.0.

Workarounds:

If you are using multiple wildcard parameters, you can check the regex output with a tool such as https://makenowjust-labs.github.io/recheck/playground/ to confirm whether a path is vulnerable.

Database specific

{
    "cwe_ids": [
        "CWE-1333"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4923.json",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "8.0.0"
                },
                {
                    "fixed": "8.4.0"
                }
            ]
        }
    ],
    "cna_assigner": "openjs"
}

References

Affected packages

Git / github.com/pillarjs/path-to-regexp

Affected ranges

Type

GIT

Repo

https://github.com/pillarjs/path-to-regexp

Events

Introduced

ed1095e0fa78a692e7f3d489e383e7bb1f9d2cc4

Fixed

34cb451ddaeea4783a2fe60579ffb3e4ccfc73a7

Database specific

{
    "cpe": "cpe:2.3:a:pillarjs:path-to-regexp:*:*:*:*:*:node.js:*:*",
    "source": "CPE_RANGE",
    "extracted_events": [
        {
            "introduced": "8.0.0"
        },
        {
            "fixed": "8.4.0"
        }
    ]
}

Affected versions

v8.*

v8.0.0

v8.1.0

v8.2.0

v8.3.0

Database specific

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-4923.json"