CVE-2026-33671
Description
A flaw was found in Picomatch, a JavaScript glob matcher. This Regular Expression Denial of Service (ReDoS) vulnerability allows a remote attacker to cause excessive CPU consumption and block the Node.js event loop, leading to a denial of service. This occurs when untrusted users supply crafted extglob patterns, specifically those using quantifiers like +() and *() combined with overlapping alternatives or nested extglobs, which can trigger catastrophic backtracking in the compiled regular expressions.
Mitigation
To mitigate this issue, applications using Picomatch should avoid passing untrusted glob patterns for compilation or matching. Implementations can disable extglob support for untrusted patterns by setting `noextglob: true` in Picomatch configurations. Alternatively, reject or sanitize patterns containing nested extglobs or specific extglob quantifiers like `+()` and `*()`. Enforcing strict allowlists for accepted pattern syntax can also reduce exposure. If the application is a service, consider running the matching process in an isolated worker or separate process with time and resource limits, and apply application-level request throttling and input validation for any endpoint that accepts glob patterns. No service restart or reload is typically required for these application-level configuration changes, but verify the specific application's behavior.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Attackers can create crafted inputs that intentionally cause the regular expression to use excessive backtracking in a way that causes the CPU consumption to spike.
Frequently Asked Questions
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