What’s Vulnerable › Vulnerabilities

CVE-2021-43842: Stored XSS via SVG file upload in Wiki.js

• Severity: low (CVSS 3.5 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-12-20 · updated 2026-06-17
• Weakness: CWE-79

Description

Wiki.js is a wiki app built on Node.js. Wiki.js versions 2.5.257 and earlier are vulnerable to stored cross-site scripting through a SVG file upload. By creating a crafted SVG file, a malicious Wiki.js user may stage a stored cross-site scripting attack. This allows the attacker to execute malicious JavaScript when the SVG is viewed directly by other users. Scripts do not execute when loaded inside a page via normal `<img>` tags. Commit 5d3e81496fba1f0fbd64eeb855f30f69a9040718 fixes this vulnerability by adding an optional (enabled by default) SVG sanitization step to all file uploads that match the SVG mime type. As a workaround, disable file upload for all non-trusted users. Wiki.js version 2.5.260 is the first production version to contain a patch. Version 2.5.258 is the first development build to contain a patch and is available only as a Docker image as requarks/wiki:canary-2.5.258.

Affected products

• Requarks wiki: through 2.5.257

References

• https://github.com/Requarks/wiki/commit/5d3e81496fba1f0fbd64eeb855f30f69a9040718
• https://github.com/Requarks/wiki/releases/tag/2.5.260
• https://github.com/Requarks/wiki/security/advisories/GHSA-3qv4-gp35-rgh7
• https://github.com/Requarks/wiki/commit/5d3e81496fba1f0fbd64eeb855f30f69a9040718
• https://github.com/Requarks/wiki/releases/tag/2.5.260
• https://github.com/Requarks/wiki/security/advisories/GHSA-3qv4-gp35-rgh7

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