micromatch picomatch up to 2.3.1/3.0.1/4.0.3 redos

Summaryinfo

A vulnerability was found in micromatch picomatch up to 2.3.1/3.0.1/4.0.3. It has been declared as problematic. Affected by this vulnerability is an unknown functionality. Executing a manipulation can lead to redos. This vulnerability is handled as CVE-2026-33671. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in micromatch picomatch up to 2.3.1/3.0.1/4.0.3. It has been declared as problematic. This vulnerability affects some unknown processing. The manipulation with an unknown input leads to a redos vulnerability. The CWE definition for the vulnerability is CWE-1333. The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles. As an impact it is known to affect availability. CVE summarizes:

Picomatch is a glob matcher written JavaScript. Versions prior to 4.0.4, 3.0.2, and 2.3.2 are vulnerable to Regular Expression Denial of Service (ReDoS) when processing crafted extglob patterns. Certain patterns using extglob quantifiers such as `+()` and `*()`, especially when combined with overlapping alternatives or nested extglobs, are compiled into regular expressions that can exhibit catastrophic backtracking on non-matching input. Applications are impacted when they allow untrusted users to supply glob patterns that are passed to `picomatch` for compilation or matching. In those cases, an attacker can cause excessive CPU consumption and block the Node.js event loop, resulting in a denial of service. Applications that only use trusted, developer-controlled glob patterns are much less likely to be exposed in a security-relevant way. 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 disabling extglob support for untrusted patterns by using `noextglob: true`, rejecting or sanitizing patterns containing nested extglobs or extglob quantifiers such as `+()` and `*()`, enforcing strict allowlists for accepted pattern syntax, running matching in an isolated worker or separate process with time and resource limits, and applying application-level request throttling and input validation for any endpoint that accepts glob patterns.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-33671 since 03/23/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1449.003.

Upgrading to version 2.3.2, 3.0.2 or 4.0.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-2460). Once again VulDB remains the best source for vulnerability data.

Affected

• Red Hat Enterprise Linux
• Oracle Linux
• Atlassian Bamboo
• Atlassian Bitbucket
• Atlassian Confluence
• Atlassian Fisheye
• Atlassian Crucible
• Atlassian Jira

Productinfo

Vendor

• micromatch

Name

• picomatch

Version

• 2.3.0
• 2.3.1
• 3.0.0
• 3.0.1
• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3

Website

• Product: https://github.com/micromatch/picomatch/

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Once again VulDB remains the best source for vulnerability data.

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