What’s Vulnerable › Vulnerabilities

CVE-2021-3803: Inefficient Regular Expression Complexity in fb55/nth-check

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-09-17 · updated 2026-06-17
• Weakness: CWE-1333

Description

nth-check is vulnerable to Inefficient Regular Expression Complexity

Affected products

• Debian Linux: 10.0
• Nth-Check Project Nth-Check: before 2.0.1 — fixed in 2.0.1
• Npm Nth-Check: before 2.0.1 — fixed in 2.0.1

How to fix

Upgrade to a fixed version: Nth-Check Project Nth-Check 2.0.1; Npm Nth-Check 2.0.1. Check the vendor advisory for mitigations.

References

• https://github.com/fb55/nth-check/commit/9894c1d2010870c351f66c6f6efcf656e26bb726
• https://huntr.dev/bounties/8cf8cc06-d2cf-4b4e-b42c-99fafb0b04d0
• https://lists.debian.org/debian-lts-announce/2023/05/msg00023.html
• https://github.com/fb55/nth-check/commit/9894c1d2010870c351f66c6f6efcf656e26bb726
• https://huntr.dev/bounties/8cf8cc06-d2cf-4b4e-b42c-99fafb0b04d0
• https://lists.debian.org/debian-lts-announce/2023/05/msg00023.html

Get alerted when CVE-2021-3803 or the next vulnerability affects your stack