CVE-2026-13764: Masterstudy - Education WordPress Theme <= 4.8.151 - Missing Authorization to Authenticated (Subscriber+) Privilege Escalation

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 10 Nov 2026.

VulnCheck KEV lists it since 12 Nov 2026. It cites 1 public report, the first from 12 Nov 2026.

• patchstack.com

How likely is exploitation in the next 30 days?

Not yet scored. FIRST's EPSS model has no score for this record as of 12 Nov 2026.

How severe?

8.8 High

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

No patch or vendor advisory is listed in the CVE record. Check StylemixThemes's advisories.

Which versions are affected?

Affected

• 4.8.151 and earlier

Versions by product

Source: CISA KEV 2026.11.10, as of 10 Nov 2026; VulnCheck KEV, as of 13 Nov 2026; FIRST EPSS, as of 12 Nov 2026; CVE List, as of 13 Nov 2026. About the data.

Description

Masterstudy - Education WordPress Theme <= 4.8.151 - Missing Authorization to Authenticated (Subscriber+) Privilege Escalation

The Masterstudy - Education WordPress Theme theme for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 4.8.151. This is due to missing authorization and nonce validation on the `masterstudy_ms_stm_set_discard_transient` AJAX action. This makes it possible for authenticated attackers, with Subscriber-level access and above, to elevate their privileges to Administrator by setting the `stm_developer_access_token` transient and using the developer access auto-login flow to obtain administrator session cookies.

Source: CVE List, as of 13 Nov 2026. About the data.

What to do

Advisories and patches

No patch, vendor advisory or mitigation is listed in the CVE record. Check StylemixThemes's own security advisories for a fix, and compare your version with the affected versions below.

This summary is based on the CVE record as of 13 Nov 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 13 Nov 2026. About the data.

Timeline