Picomatch is a glob matcher written JavaScript. Versions prior to 4.0.4, 3.0.2, and 2.3.2 are vulnerable to a method injection vulnerability affecting the `POSIX_REGEX_SOURCE` object. Because the object inherits from `Object.prototype`, specially crafted POSIX bracket expressions (e.g., `[[:constructor:]]`) can reference inherited method names. These methods are implicitly converted to strings and injected into the generated regular expression. This leads to incorrect glob matching behavior (integrity impact), where patterns may match unintended filenames. The issue does not enable remote code execution, but it can cause security-relevant logic errors in applications that rely on glob matching for filtering, validation, or access control. All users of affected `picomatch` versions that process untrusted or user-controlled glob patterns are potentially impacted. This issue is fixed in picomatch 4.0.4, 3.0.2 and 2.3.2. Users should upgrade to one of these versions or later, depending on their supported release line. If upgrading is not immediately possible, avoid passing untrusted glob patterns to picomatch. Possible mitigations include sanitizing or rejecting untrusted glob patterns, especially those containing POSIX character classes like `[[:...:]]`; avoiding the use of POSIX bracket expressions if user input is involved; and manually patching the library by modifying `POSIX_REGEX_SOURCE` to use a null prototype.
History

Fri, 27 Mar 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 27 Mar 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-624
References
Metrics threat_severity

None

threat_severity

Moderate


Fri, 27 Mar 2026 08:45:00 +0000

Type Values Removed Values Added
First Time appeared Micromatch
Micromatch picomatch
Vendors & Products Micromatch
Micromatch picomatch

Thu, 26 Mar 2026 22:00:00 +0000

Type Values Removed Values Added
Description Picomatch is a glob matcher written JavaScript. Versions prior to 4.0.4, 3.0.2, and 2.3.2 are vulnerable to a method injection vulnerability affecting the `POSIX_REGEX_SOURCE` object. Because the object inherits from `Object.prototype`, specially crafted POSIX bracket expressions (e.g., `[[:constructor:]]`) can reference inherited method names. These methods are implicitly converted to strings and injected into the generated regular expression. This leads to incorrect glob matching behavior (integrity impact), where patterns may match unintended filenames. The issue does not enable remote code execution, but it can cause security-relevant logic errors in applications that rely on glob matching for filtering, validation, or access control. All users of affected `picomatch` versions that process untrusted or user-controlled glob patterns are potentially impacted. This issue is fixed in picomatch 4.0.4, 3.0.2 and 2.3.2. Users should upgrade to one of these versions or later, depending on their supported release line. If upgrading is not immediately possible, avoid passing untrusted glob patterns to picomatch. Possible mitigations include sanitizing or rejecting untrusted glob patterns, especially those containing POSIX character classes like `[[:...:]]`; avoiding the use of POSIX bracket expressions if user input is involved; and manually patching the library by modifying `POSIX_REGEX_SOURCE` to use a null prototype.
Title Picomatch: Method Injection in POSIX Character Classes causes incorrect Glob Matching
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-03-26T21:39:16.362Z

Updated: 2026-03-27T13:58:41.846Z

Reserved: 2026-03-23T16:34:59.930Z

Link: CVE-2026-33672

cve-icon Vulnrichment

Updated: 2026-03-27T13:31:42.669Z

cve-icon NVD

Status : Received

Published: 2026-03-26T22:16:30.387

Modified: 2026-03-26T22:16:30.387

Link: CVE-2026-33672

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-26T21:39:16Z

Links: CVE-2026-33672 - Bugzilla