CVE-2026-67335 json
better-auth before 1.6.2 OAuth State Validation Bypass
published 2026-05-15 5 mo ago modified 2026-09-08 2 mo ago also EUVD-2026-51852 , GHSA-wxw3-q3m9-c3jr
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 20%
- public exploits
- 0
- none known
Summary
better-auth versions before 1.6.2 fail to validate the OAuth state parameter against the stored nonce when using cookie-backed state storage without PKCE. Attackers can forge the state parameter and supply an attacker-controlled authorization code to create authenticated sessions bound to the attacker's external identity or persistently link attacker accounts to victim profiles.
Patch / fix
- npm better-auth 1.6.2
- better-auth better-auth 1.6.2
- github.com/better-auth/better-auth@9deb793 commit
- github.com/better-auth/better-auth#8949 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.0 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N |
| CNA | 4.0 | 6.0 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | better-auth | <1.6.2 |
1.6.2 |
Affected products
- better-auth better-auth
Classification
References
-
github.com
/better-auth/better-auth/pull/8949
web
-
github.com
/better-auth/better-auth/commit/9deb7936aba7931f2db4b460141f476508f11bfd
web
-
github.com
/better-auth/better-auth/security/advisories/GHSA-wxw3-q3m9-c3jr
vendor-advisory, web
-
vulncheck.com
/advisories/better-auth-before-oauth-state-validation-bypass
third-party-advisory
-
github.com
/better-auth/better-auth/issues/8897
web
-
github.com
/better-auth/better-auth
package
Sources
- CVE List CVE-2026-67335
- GitHub Advisory GHSA-wxw3-q3m9-c3jr
- NVD CVE-2026-67335
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.