What is CVE-2021-3649?

CVE-2021-3649 is a high-severity vulnerability in Chatwoot, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2021-07-16.

How severe is CVE-2021-3649?

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

Vulnerability in Chatwoot

CVE-2021-3649

chatwoot is vulnerable to Inefficient Regular Expression Complexity

Vulnerability class: ReDoS (Regular Expression Denial of Service)

Published 2021-07-16 · 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: 0.012 (67.5th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 67.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Chatwoot
Chatwoot Chatwoot/chatwoot — versions unspecified

Weakness classification (CWE)

CWE-1333 — Inefficient Regular Expression Complexity

References

huntr.dev/bounties/1625088985607-chatwoot/chatwoot (Exploit, Patch, Third Party Advisory, Issue Tracking)
github.com/chatwoot/chatwoot/commit/aa7db90cd2d23dbcf22a94f1e4c100dd909e2172 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3649?: CVE-2021-3649 is a high-severity vulnerability in Chatwoot, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2021-07-16.
How severe is CVE-2021-3649?: High severity. CVSS v3 base score is 7.5 out of 10.