What is CVE-2021-43308?

CVE-2021-43308 is a medium-severity vulnerability in Markdown-Link-Extractor, classified under Inefficient Regular Expression Complexity. CVSS score: 5.9/10. Published 2022-06-02.

How severe is CVE-2021-43308?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Vulnerability in Markdown-Link-Extractor

CVE-2021-43308

An exponential ReDoS (Regular Expression Denial of Service) can be triggered in the markdown-link-extractor npm package, when an attacker is able to supply arbitrary input to the module's exported function

Vulnerability class: ReDoS (Regular Expression Denial of Service)

Published 2022-06-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.011 (63.8th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 63.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Markdown-Link-Extractor — versions unspecified
Markdown-Link-Extractor Project — versions 4.0.0

Weakness classification (CWE)

CWE-1333 — Inefficient Regular Expression Complexity

References

research.jfrog.com/vulnerabilities/markdown-link-extractor-redos-xray-211350/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-43308?: CVE-2021-43308 is a medium-severity vulnerability in Markdown-Link-Extractor, classified under Inefficient Regular Expression Complexity. CVSS score: 5.9/10. Published 2022-06-02.
How severe is CVE-2021-43308?: Medium severity. CVSS v3 base score is 5.9 out of 10.