CVE-2021-37700Clipboard-based DOM-XSS
- 6.5MediumCVSS base score
- 1.7%Exploitation in 30 daysEPSS · top 23% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
@github/paste-markdown is an npm package for pasting markdown objects. A self Cross-Site Scripting vulnerability exists in the @github/paste-markdown before version 0.3.4. If the clipboard data contains the string `<table>`, a **div** is dynamically created, and the clipboard content is copied into its **innerHTML** property without any sanitization, resulting in improper execution of JavaScript in the browser of the victim (the user who pasted the code). Users directed to copy text from a malicious website and paste it into pages that utilize this library are affected. This is fixed in version 0.3.4. Refer the to the referenced GitHub Advisory for more details including an example exploit.
Timeline
ID reserved
By GitHub_M
- 14 days later
· 14 days later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| NVDNVD · Modified | 3.1 | Medium6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 1.7% · top 23% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Affected products
- affected < 0.3.4
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npm@github/paste-markdownGHSA-gpfj-4j6g-c4w9 (opens in a new tab)
References
References4
- https://github.com/github/paste-markdown/security/advisories/GHSA-gpfj-4j6g-c4w9 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/github/paste-markdown/commit/32b7ea3f29ae8f256f9d19768387be42678ddf30 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/github/paste-markdown/releases/tag/v0.3.4 (opens in a new tab)x_refsource_MISCx_transferred
- https://www.npmjs.com/package/%40github/paste-markdown (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-1726 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-gpfj-4j6g-c4w9 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-37700)Record last updated .