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Fencer Vulns
medium 6.1

CVE-2026-19712 json

Masteriyo LMS < 2.3.3 - Instructor+ Stored XSS via Quiz Description

published 2026-08-16 2 mo ago modified 2026-08-26 2 mo ago also EUVD-2026-59915

cvss
6.1
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 16%
public exploits
0
none known

Summary

The Masteriyo LMS WordPress plugin before 2.3.3 does not sanitise and escape a quiz field before outputting it back in a page, and grants its instructor role the ability to store unfiltered HTML, allowing such users to perform Stored Cross-Site Scripting attacks against any visitor of the affected page, including administrators. This affects default single-site installations. Sites running multisite, or defining DISALLOW_UNFILTERED_HTML, are not affected as the capability is not granted there.

Patch / fix

  • Unknown Masteriyo LMS 2.3.3

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/08c31101-ee38-46e9-b451-abb1ed70079c/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

  • Unknown Masteriyo LMS

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
Technology feeds

References

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.