How severe is GHSA-mmh6-m7v9-5956?

No CVSS score has been assigned to GHSA-mmh6-m7v9-5956 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-mmh6-m7v9-5956?

GHSA-mmh6-m7v9-5956 affects the following packages: markdown-link-extractor (npm), markdown-link-extractor (npm). Ecosystems affected: npm.

How do I fix GHSA-mmh6-m7v9-5956?

Update markdown-link-extractor to 3.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mmh6-m7v9-5956 is resolved across your whole dependency graph.

How do I detect GHSA-mmh6-m7v9-5956 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for markdown-link-extractor, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-mmh6-m7v9-5956 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is GHSA-mmh6-m7v9-5956 actively exploited in the wild?

Yes. There are 1 known exploit references for GHSA-mmh6-m7v9-5956, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for GHSA-mmh6-m7v9-5956?

GHSA-mmh6-m7v9-5956 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 66th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-mmh6-m7v9-5956?

GHSA-mmh6-m7v9-5956 is classified as CWE-1333 (CWE-1333). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-mmh6-m7v9-5956 published, and has it been updated?

GHSA-mmh6-m7v9-5956 was published on June 3, 2022 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

Regular expression denial of service in markdown-link-extractorGHSA-mmh6-m7v9-5956

GHSA-mmh6-m7v9-5956 is a CWE-1333 vulnerability in markdown-link-extractor. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for markdown-link-extractor — see the affected versions and patch details below.

Also known asCVE-2021-43308

Published

Jun 3, 2022

Updated

Nov 8, 2023

Affected

2 pkgs

Patched

2 / 2

Exploits

1 known

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs66th percentile — riskier than 66% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

98other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

markdown-link-extractornpm

280Kdownloads / week

Description

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

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`markdown-link-extractor`	all versions	3.0.2`npm install markdown-link-extractor@3.0.2`
📦npm	`markdown-link-extractor`	≥ 4.0.0&&< 4.0.1	4.0.1`npm install markdown-link-extractor@4.0.1`

Affected Products

1 product · 2 configurations

Application

markdown-link-extractormarkdown-link-extractor_project

< 3.0.2

1 version

4.0.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

An exponential ReDoS (Regular Expression Denial of Service) can be trigg…

research.jfrog.comNVDJun 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for markdown-link-extractor, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update markdown-link-extractor to 3.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mmh6-m7v9-5956 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.