CVE-2021-21383

Name: CVE-2021-21383
Creator: NVD / NIST
Published: 2021-03-18T17:15:13.947+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 0.88%

Last modified Jun 17, 2026

CVE-2021-21383 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. Wiki.js an open-source wiki app built on Node.js. Wiki.js before version 2.5.191 is vulnerable to stored cross-site scripting through mustache expressions in code blocks. EPSS estimates a 0.88% chance of exploitation in the next 30 days.

Description

Wiki.js an open-source wiki app built on Node.js. Wiki.js before version 2.5.191 is vulnerable to stored cross-site scripting through mustache expressions in code blocks. This vulnerability exists due to mustache expressions being parsed by Vue during content injection even though it is contained within a `<pre>` element. By creating a crafted wiki page, a malicious Wiki.js user may stage a stored cross-site scripting attack. This allows the attacker to execute malicious JavaScript when the page is viewed by other users. For an example see referenced GitHub Security Advisory. Commit 5ffa189383dd716f12b56b8cae2ba0d075996cf1 fixes this vulnerability by adding the v-pre directive to all `<pre>` tags during the render.

Metrics

CVSS 3.1

5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.88%

54.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Requarks	Wiki.Js	< 2.5.191

References

https://github.com/Requarks/wiki/commit/5ffa189383dd716f12b56b8cae2ba0d075996cf1Patch, Third Party Advisory
https://github.com/Requarks/wiki/releases/tag/2.5.191Release Notes, Third Party Advisory
https://github.com/Requarks/wiki/security/advisories/GHSA-6xx4-m8gx-826rExploit, Patch, Third Party Advisory
https://github.com/Requarks/wiki/commit/5ffa189383dd716f12b56b8cae2ba0d075996cf1Patch, Third Party Advisory
https://github.com/Requarks/wiki/releases/tag/2.5.191Release Notes, Third Party Advisory
https://github.com/Requarks/wiki/security/advisories/GHSA-6xx4-m8gx-826rExploit, Patch, Third Party Advisory

Timeline

Published: Mar 18, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21383?

How severe is CVE-2021-21383?

CVE-2021-21383 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.88% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21383?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21383?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST