Prototype Pollution in sheetJS

published 2023-04-24 3 y ago modified 2026-06-17 4 mo ago also GHSA-4r6h-8v6p-xvw6 , EUVD-2023-1194

cvss: 7.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.0%; EPSS 1.0% chance of exploitation in 30 days, percentile 62%
public exploits: 0; none known

SheetJS Community Edition before 0.19.3 allows Prototype Pollution via a crafted file. In other words. 0.19.2 and earlier are affected, whereas 0.19.3 and later are unaffected.

Patch / fix

fixed in 1

sheetjs sheetjs 0.19.3

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 21 mo ago (2025-02-04)

Exploit prediction

0.99% chance of exploitation in the next 30 days, higher than 62% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
GitHub	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	xlsx	all versions	no fix listed

Classification

Weakness

CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

cdn.sheetjs.com /advisories/CVE-2023-30533
web, vendor-advisory
git.sheetjs.com /sheetjs/sheetjs/src/branch/master/CHANGELOG.md
web, release-notes
git.sheetjs.com /sheetjs/sheetjs/issues/2986
web
nvd.nist.gov /vuln/detail/CVE-2023-30533
advisory
cdn.sheetjs.com
web
git.sheetjs.com /sheetjs/sheetjs
package
git.sheetjs.com /sheetjs/sheetjs/issues/2667
web

Sources

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.

Summary