sanitize-svg Filter Bypass Allows Cross-Site Scripting (XSS)

published 2023-01-04 3 y ago modified 2026-06-17 4 mo ago also GHSA-h857-2g56-468g , EUVD-2023-0483

cvss: 7.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits: 0; none known

The `sanitize-svg` package, a small SVG sanitizer to prevent cross-site scripting attacks, uses a deny-list-pattern to sanitize SVGs to prevent XSS. In doing so, literal `<script>`-tags and on-event handlers were detected in versions prior to 0.4.0. As a result, downstream software that relies on `sanitize-svg` and expects resulting SVGs to be safe, may be vulnerable to cross-site scripting. This vulnerability was addressed in v0.4.0. There are no known workarounds

Patch / fix

fixed in 2 links 1

npm @mattkrick/sanitize-svg 0.4.0
sanitize-svg_project sanitize-svg 0.4.0

github.com/mattkrick/sanitize-svg@b107e45 commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 20 mo ago (2025-03-10)

Exploit prediction

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/mattkrick/sanitize-svg/security/advisories/GHSA-h857-2g56-468g referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
GitHub	3.1	7.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	@mattkrick/sanitize-svg	<0.4.0	0.4.0

Affected products

mattkrick sanitize-svg

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation
CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page

References

github.com /mattkrick/sanitize-svg/commit/b107e453ede7b58adcccae74a3e474c012eec85d
web, patch, third-party-advisory
github.com /mattkrick/sanitize-svg/security/advisories/GHSA-h857-2g56-468g
web, exploit, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2023-22461
advisory
github.com /mattkrick/sanitize-svg
package

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