Answer in brief
CVE-2022-21680 records a High severity (CVSS 7.5) vulnerability in Inefficient Regular Expression Complexity in marked. The current sources do not mark it as known exploited. The current feed maps marked (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps marked (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| markednpm | >=0 <4.0.10 | 4.0.10 |
Published upstream
Jan 14, 2022
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Sep 10, 2026
### 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 without upgrading?_ Do not run untrusted markdown through marked or run marked on a [worker](https://marked.js.org/using_advanced#workers) thread and set a reasonable time limit to prevent draining resources. ### References _Are there any links users can visit to find out more?_ - https://marked.js.org/using_advanced#workers - https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS ### For more information If you have any questions or comments about this advisory: * Open an issue in [marked](https://github.com/markedjs/marked)
Quoted source text, attributed separately from HOL analysis.