There is a Cross-Site Scripting vulnerability in Microsoft Clarity version 0.3.

published 2021-11-19 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-20524

cvss: 5.4; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.6%; EPSS 1.6% chance of exploitation in 30 days, percentile 75%
public exploits: 0; none known

There is a Cross-Site Scripting vulnerability in Microsoft Clarity version 0.3. The XSS payload executes whenever the user changes the clarity configuration in Microsoft Clarity version 0.3. The payload is stored on the configuring project Id page.

Exploit prediction

1.60% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

cybersecurityworks.com https://cybersecurityworks.com/zerodays/cve-2021-33850-stored-cross-site-scripting-xss-in-wordpress-microsoft-clarity-plugin.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	3.5	AV:N/AC:M/Au:S/C:N/I:P/A:N

Affected products

n/a Microsoft Clarity

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

Technology feeds

WordPress rss critical rss

References

cybersecurityworks.com /zerodays/cve-2021-33850-stored-cross-site-scripting-xss-in-wordpress-microsoft-clarity-plugin.html
exploit, third-party-advisory

Sources

CVE List CVE-2021-33850
NVD CVE-2021-33850

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