Generation of Predictable Email Confirmation Token in ATutor

published 2026-08-20 2 mo ago modified 2026-10-27 12 d ago also EUVD-2026-63364

cvss: 6.3; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits: 0; none known

ATutor generates predictable email confirmation tokens due to the use of insufficiently random values in the account confirmation functionality. Due to the use of predictable values related to user registration, an attacker who knows or can predict these values can guess valid account activation tokens. This allows an attacker to activate an unconfirmed account without access to the victim's email inbox. Product is no longer actively supported and the vulnerabilities have not been fixed. Only version 2.2.4 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-20)

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.3	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA	4.0	6.3	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

ATutor ATutor

Classification

Weakness

CWE-340 Generation of Predictable Numbers or Identifiers

References

cert.pl /en/posts/2026/08/CVE-2026-64960
third-party-advisory
atutor.github.io /
product

Sources

CVE List CVE-2026-64964
NVD CVE-2026-64964

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