by Kastro
Paper/Archive/CVE-2026-121802

CVE-2026-121802

better-auth Better Auth — @better-auth/expo before 1.7.16 allows certain account-takeover outcomes (e.g., unauthenticated changes of any account's email address),…

CVSS 9.1
critical.is priorityof 100
27
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0No EPSS score.000 × 200.0No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

@better-auth/expo before 1.7.16 allows certain account-takeover outcomes (e.g., unauthenticated changes of any account's email address), because it signs a caller-supplied state value without checking whether that value had been issued by the server. NOTE: the application secret must be rotated after updating to a fixed version.

Affected

ProductAffectedFixed inSource
Better Auth< 1.7.161.7.16CNA

Scores by source

mitre (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References

refgithub.com/better-auth/better-auth/security/advisories/GHSA-4wq4-2ppv-q3hgrefgithub.com/better-auth/better-auth/blob/main/packages/expo/CHANGELOG.mdrefgithub.com/better-auth/better-auth/releases/tag/v1.7.16