CVE-2021-43842

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account, but needs a user to act. Limited direct impact.

Exploit odds

0.7% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-12-20 23:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:11 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.7% in the next 30 days (EPSS).
• Severity: 5.4 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-12-20 23:15 UTC

Last modified

2026-06-17 04:11 UTC

Exploit probability

0.7% · EPSS, next 30 days

Weakness

CWE-79 · Cross-site scripting

Record status

Modified

Affected

• Requarks wiki.js ≤ 2.5.257

Attack profile CVSS 3.1 · 5.4

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-43842.md and follow it. Check whether this project is affected by CVE-2021-43842. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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