How severe is CVE-2022-21680?

CVE-2022-21680 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2022-21680?

CVE-2022-21680 affects the following packages: marked (npm). Ecosystems affected: npm.

How do I fix CVE-2022-21680?

Update marked to 4.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-21680 is resolved across your whole dependency graph.

How do I detect CVE-2022-21680 in my npm dependencies?

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

How do I mitigate CVE-2022-21680 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 CVE-2022-21680 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2022-21680, 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 CVE-2022-21680?

CVE-2022-21680 has an EPSS (Exploit Prediction Scoring System) score of 2.9%, placing it in the 87th 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 CVE-2022-21680?

CVE-2022-21680 is classified as Uncontrolled Resource Consumption (CWE-400), CWE-1333 (CWE-1333). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2022-21680 published, and has it been updated?

CVE-2022-21680 was published on January 14, 2022 and was last updated on October 28, 2026. 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

HIGH severity

CVE-2022-21680 — marked

HIGHFix: markedjs/marked@c4a3ccd

CVE-2022-21680 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in marked. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for marked — see the affected versions and patch details below.

Cubic catastrophic backtracking (ReDoS) in marked

Also known asGHSA-rrrm-qjm4-v8hf

Published

Jan 14, 2022

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs87th percentile — riskier than 87% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg 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.

15Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

markednpm

121.1Mdownloads / week

Description

Impact

What kind of vulnerability is it?

Denial of service.

The regular expression block.def may cause catastrophic backtracking against some strings. PoC is the following.

import * as marked from "marked";

marked.parse(`[x]:${' '.repeat(1500)}x ${' '.repeat(1500)} x`);

Who is impacted?

Anyone who runs untrusted markdown through marked and does not use a worker with a time limit.

Patches

Has the problem been patched?

Yes

What versions should users upgrade to?

4.0.10

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

Do not run untrusted markdown through marked or run marked on a worker thread and set a reasonable time limit to prevent draining resources.

References

Are there any links users can visit to find out more?

For more information

If you have any questions or comments about this advisory:

Open an issue in marked

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`marked`	all versions	4.0.10`npm install marked@4.0.10`

Affected Products

2 products · 2 configurations

fedorafedoraproject

1 version

Application

markedmarked_project

< 4.0.10

range

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.

Marked is a markdown parser and compiler. Prior to version 4.0.10, the r…

github.comNVDJan 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for marked, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update marked to 4.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-21680 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.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
Red Hat Ceph Storage 6.1	`rhceph/rhceph-6-dashboard-rhel9:6-75`	RHSA-2023:3642

Frequently Asked Questions

### Impact _What kind of vulnerability is it?_ Denial of service. The regular expression `block.def` may cause catastrophic backtracking against some strings. PoC is the following. ```javascript import * as marked from "marked"; marked.parse(`[x]:${' '.repeat(1500)}x ${' '.repeat(1500)} x`); ``` _Who is impacted?_ Anyone who runs untrusted markdown through marked and does not use a worker with a time limit. ### Patches _Has the problem been patched?_ Yes _What versions should users upgrade to?_ 4.0.10 ### Workarounds _Is there a way for users to fix or remediate the vulnerability