High severity · published Oct 12, 2026
CVE-2026-109346
better-auth 1.3.8-beta.3 before 1.7.0-rc.3 Device Authorization Phishing via /device
8.1
CVSS
0.3%
EPSS
No
On KEV
Description
better-auth from 1.3.8-beta.3 before 1.7.0-rc.3 contains a UI misrepresentation vulnerability in the deviceAuthorization plugin because GET /device omits the requesting client_id and scope. Attackers can start a device request via /device/code, trick signed-in users into approving the code, then redeem it at /device/token for a live session token.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BE
better-auth · better-auth
1.3.8-beta.3 before 1.7.0-rc.3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-109346
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-109346
vendor-advisory
https://github.com/better-auth/better-auth/security/advisories/GHSA-q84f-53jg-9ppm
third-party-advisory
https://www.vulncheck.com/advisories/better-auth-1.3.8-beta.3-before-1.7.0-rc.3-device-authorization-phishing-via-device
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