What is CVE-2026-33671?

CVE-2026-33671 is a high-severity vulnerability in Micromatch Picomatch, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2026-03-26.

How severe is CVE-2026-33671?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2026-33671 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Micromatch Picomatch

CVE-2026-33671

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 s…

Vulnerability class: ReDoS (Regular Expression Denial of Service)

EPSS: 0.000 (5.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Micromatch Picomatch — versions >= 4.0.0, < 4.0.4, >= 3.0.0, < 3.0.2, < 2.3.2

Weakness classification (CWE)

CWE-1333 — Inefficient Regular Expression Complexity

Public proof-of-concept exploits

BeLazy167/next-picomatch-cve-repro

References

https://github.com/micromatch/picomatch/security/advisories/GHSA-c2c7-rcm5-vvqj (x_refsource_CONFIRM)
https://github.com/micromatch/picomatch/commit/5eceecd27543b8e056b9307d69e105ea03618a7d (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-33671?: CVE-2026-33671 is a high-severity vulnerability in Micromatch Picomatch, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2026-03-26.
How severe is CVE-2026-33671?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2026-33671 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.