CVE-2026-100679 (CVSS 8.8)

Description

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.

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CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0032

Probability of exploitation

0.23%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-639 CWE-639

References

Other References

https://github.com/stoatchat/stoatchat/security/advisories/GHSA-gwg6-q3c3-97cx https://www.vulncheck.com/advisories/stoatchat-before-0.15.5-mfa-bypass-via-cross-account-ticket https://github.com/stoatchat/stoatchat/security/advisories/GHSA-gwg6-q3c3-97cx

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-100679? +

CVE-2026-100679 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0032, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-100679? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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