What is CVE-2021-3804?

CVE-2021-3804 is a high-severity vulnerability in Nervjs Nervjs/taro, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2021-09-17.

How severe is CVE-2021-3804?

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

Vulnerability in Nervjs Nervjs/taro

CVE-2021-3804

taro is vulnerable to Inefficient Regular Expression Complexity

Vulnerability class: ReDoS (Regular Expression Denial of Service)

Published 2021-09-17 · 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 (68.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 68.5% 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

Nervjs Nervjs/taro — versions unspecified
Taro

Weakness classification (CWE)

CWE-1333 — Inefficient Regular Expression Complexity

References

huntr.dev/bounties/0ebe85e6-cc85-42b8-957e-18d8df277414 (Exploit, Patch, Third Party Advisory, Issue Tracking)
github.com/nervjs/taro/commit/acadb6c826ba57f2030a626f1de4f7b4608fcdb5 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3804?: CVE-2021-3804 is a high-severity vulnerability in Nervjs Nervjs/taro, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2021-09-17.
How severe is CVE-2021-3804?: High severity. CVSS v3 base score is 7.5 out of 10.