8.5

CVE-2026-66399: phpMyFAQ before 4.1.6 Privilege Escalation via Group Membership

Deferred
Published 27-07-2026Last modified 18-08-2026

Vulnerability summary

CVE-2026-66399 is a high (CVSS 8.5) Improper Privilege Management vulnerability in thorsten phpmyfaq. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 33.3% of scored vulnerabilities.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.5/10
010
High · v4.0 (CVE.org)
EPSS score
0.40%
0%100%
Low · +0.17 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 27-07-2026
    PublishedVulnerability first disclosed.
  2. 18-08-2026
    Last modifiedVulnerability information updated.

Description

phpMyFAQ before 4.1.6 contains a privilege escalation vulnerability in GroupController::updateMembers() that allows administrators with only group-management permissions to join privileged groups without verification of required rights. Attackers can add themselves to pre-existing groups holding user-management rights and immediately inherit those permissions to modify or delete user accounts.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

Increase +0.17 pp

From 0.23% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Thorsten1 product

1 vendor · 1 product

References

2 links