CVE-2021-43308 json
Exponential ReDoS in markdown-link-extractor
published 2022-06-01 4 y ago modified 2026-06-17 4 mo ago also GHSA-mmh6-m7v9-5956 , EUVD-2022-6096
- cvss
- 5.9
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 65%
- public exploits
- 0
- none known
Summary
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
Patch / fix
- npm markdown-link-extractor 3.0.2, 4.0.1
- markdown-link-extractor markdown-link-extractor 3.0.2, 4.0.1
Exploit prediction
1.10% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- research.jfrog.com https://research.jfrog.com/vulnerabilities/markdown-link-extractor-redos-xray-211350/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | markdown-link-extractor | <3.0.2 >=4.0.0, <4.0.1 |
3.0.2 4.0.1 |
Affected products
- markdown-link-extractor markdown-link-extractor
Classification
- Weakness
-
- CWE-1333 Inefficient Regular Expression Complexity
References
Sources
- CVE List CVE-2021-43308
- GitHub Advisory GHSA-mmh6-m7v9-5956
- NVD CVE-2021-43308
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.