Authentication bypass vulnerability

published 2026-07-29 3 mo ago modified 2026-10-23 16 d ago also EUVD-2026-50133

cvss: 6.5; 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 27%
public exploits: 0; none known

An authentication bypass vulnerability in Koollab LMS allowed an unauthenticated attacker to take over any account, including administrator accounts, by supplying a valid user UUID without providing primary credentials via the 2FA validation endpoint.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 3 mo ago (2026-07-29)

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Affected products

Three Learning Koollab LMS

Classification

Weakness

CWE-287 Improper Authentication

References

csa.gov.sg /alerts-and-advisories/alerts/al-2026-094/

Sources

CVE List CVE-2026-63238
NVD CVE-2026-63238

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