Fabric.js: Improper escaping in fabric.Gradient colorStops leads to XSS in SVG serialization

published 2026-06-12 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-38399 , GHSA-w22m-hvvm-xmwx

cvss: 5.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits: 0; none known

Fabric.js is a Javascript HTML5 canvas library. Prior to 7.4.0, a potential Cross-Site Scripting (XSS) vulnerability exists in Fabric.js due to improper escaping of user-controlled input during SVG serialization via the toSVG() method. Specifically, the color field within the colorStops array of a fabric.Gradient object is not properly escaped when converted into SVG <stop> elements. If an application renders the generated SVG string into the DOM, this may allow an attacker to inject arbitrary HTML/SVG and execute JavaScript in the victim's browser. This vulnerability is fixed in 7.4.0.

Patch / fix

fixed in 2 links 1

npm fabric 7.4.0
fabricjs fabric.js 7.4.0

github.com/fabricjs/fabric.js/releases/tag/v740 release

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 4 mo ago (2026-06-23)

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/fabricjs/fabric.js/security/advisories/GHSA-w22m-hvvm-xmwx referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
GitHub	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/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

Affected packages

ecosystem	package	affected	fixed in
npm	fabric	<7.4.0	7.4.0

Affected products

fabricjs fabric.js

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation
CWE-116 Improper Encoding or Escaping of Output

References

github.com /fabricjs/fabric.js/security/advisories/GHSA-w22m-hvvm-xmwx
exploit, web, mitigation, vendor-advisory
github.com /fabricjs/fabric.js/releases/tag/v740
web, product, release-notes
nvd.nist.gov /vuln/detail/CVE-2026-44311
advisory
github.com /fabricjs/fabric.js
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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary