Auth bypass in Stoatchat
CVE-2026-100679
stoatchat before 0.15.5 fails to validate that MFA tickets belong to the authenticated user, allowing attackers to bypass MFA by using their own valid ticket with another user's session token. Attackers can obtain a ticket from their own account and use it with a victim's session token to disable TOTP, view recovery codes, or perform other sensitive operations without providing the victim's credentials.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/stoatchat/stoatchat/security/advisories/GHSA-gwg6-q3c3-97cx (vendor-advisory)
- www.vulncheck.com/advisories/stoatchat-before-0.15.5-mfa-bypass-via-cross-accou… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100679?
- CVE-2026-100679 is a high-severity vulnerability in Stoatchat, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 8.8/10. Published 2026-09-26.
- How severe is CVE-2026-100679?
- High severity. CVSS v3 base score is 8.8 out of 10.