What is CVE-2021-3777?

CVE-2021-3777 is a high-severity vulnerability in Daaku Daaku/nodejs-Tmpl, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2021-09-15.

How severe is CVE-2021-3777?

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

Vulnerability in Daaku Daaku/nodejs-Tmpl

CVE-2021-3777

nodejs-tmpl is vulnerable to Inefficient Regular Expression Complexity

Vulnerability class: ReDoS (Regular Expression Denial of Service)

Published 2021-09-15 · last modified 2026-06-17.

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.

EPSS exploit prediction

EPSS: 0.013 (69.3th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Daaku Daaku/nodejs-Tmpl — versions unspecified
Tmpl Project

Weakness classification (CWE)

CWE-1333 — Inefficient Regular Expression Complexity

References

huntr.dev/bounties/a07b547a-f457-41c9-9d89-ee48bee8a4df (Exploit, Patch, Third Party Advisory, Issue Tracking)
github.com/daaku/nodejs-tmpl/commit/4c654e4d1542f329ed561fd95ccd80f30c6872d6 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3777?: CVE-2021-3777 is a high-severity vulnerability in Daaku Daaku/nodejs-Tmpl, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2021-09-15.
How severe is CVE-2021-3777?: High severity. CVSS v3 base score is 7.5 out of 10.