Skip to content
Fencer Intel
medium 4.3

CVE-2026-81339 json

MasterStudy LMS < 3.7.50 - Subscriber+ Quiz Attempt Grade Disclosure via IDOR

published last mo. modified last mo. also EUVD-2026-85029

cvss
4.3
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 19%
public exploits
0
none known

Summary

The MasterStudy LMS WordPress Plugin WordPress plugin before 3.7.50 does not perform a per-object ownership check when returning a quiz attempt result, allowing any authenticated user with a minimal (subscriber) role to read other students' quiz grades, pass/fail status and attempt timestamps by referencing an attempt identifier belonging to another user.

Patch / fix

  • Unknown MasterStudy LMS WordPress Plugin 3.7.50

Is CVE-2026-81339 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/f027d0b1-5d8a-4e80-adb3-bbf97dc53306/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected products

  • Unknown MasterStudy LMS WordPress Plugin

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key
Technology feeds

References

Sources

Fencer Intel 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.