Umami 2FA policy handler allows single-factor authentication
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-287.
Summary
Umami versions 3.3.x, 3.4.0 and 3.4.1 contain a flaw in the 2FA policy handler of the login route, where authentication uses only a single factor (CWE-308). A remote attacker with low privileges can exploit this to log in without a second factor. A public exploit has been disclosed and is linked in the references. The vendor did not respond to early contact about the disclosure.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Description from the CNA
A vulnerability has been found in Umami 3.3.x/3.4.0/3.4.1. This affects an unknown part of the file src/app/api/auth/login/route.ts of the component 2FA Policy Handler. The manipulation leads to use of single-factor authentication. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Umami | all versions; 3.4.0; 3.4.1 | — | No fix listed | CNA |
- Umami Vendor— Affected all versions; 3.4.0; 3.4.1 Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for Umami.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Timeline
- 2026-11-03 Threatist record created from CVE-2026-121531
- 2026-11-03 CISA SSVC decision points changed
- 2026-11-03 Priority changed: LOW → MEDIUM
- 2026-11-04 Alias added: GHSA-hx7r-4xfj-79cc
References
Sources
- CVE-2026-121531 · CVE Program
- CVE-2026-121531 · NVD
- FIRST EPSS
- GHSA-hx7r-4xfj-79cc · GitHub Advisory Database · CC BY 4.0
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