CVE-2026-45364

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for or the configured IP-bearing header. IPv6 clients controlling a typical /6...

Improper Authorization

Overview better-auth is a The most comprehensive authentication library for TypeScript. Affected versions of this package are vulnerable to Improper Authorization in the deviceAuthorization plugin. An attacker can gain unauthorized access to a device or deny legitimate user sign-in by submitting ...

@agent-native/core (>=0.26.5 <=0.28.5), @intlayer/backend (=8.7.0-canary.0) +6 more potentially affected by CVE-2026-45337 via better-auth (>=1.6.0 <=1.6.10)

better-auth NPM version =1.6.0, =0.26.5, =0.0.33, =0.2.0, =1.6.0, =0.1.2, =0.2.0 Source cves: CVE-2026-45337 Source advisory: SNYK:JS-BETTERAUTH-17173857...

@agent-native/core (>=0.26.5 <=0.28.5), @intlayer/backend (=8.7.0-canary.0) +6 more potentially affected by CVE-2026-45337 via better-auth (>=1.6.0 <=1.6.10)

better-auth NPM version =1.6.0, =0.26.5, =0.0.33, =0.2.0, =1.6.0, =0.1.2, =0.2.0 Source cves: CVE-2026-45337 Source advisory: OSV:GHSA-CQ3F-VC6P-68FH...

PT-2026-46307

Am I affected? You are affected if all of the following are true: - You use better-auth at a version = 1.6.0, 1.6.11. - The deviceAuthorization plugin is enabled in your auth config deviceAuthorization in your plugins array. - A third party can observe a pending user code before the legitimate us...

CVE-2026-45364

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for or the configured IP-bearing header. IPv6 clients controlling a typical /6...

CVE-2026-45364

The CVE-2026-45364 issue affects Better Auth (TypeScript) where the HTTP rate limiter keyed by the leftmost x-forwarded-for value could be bypassed for IPv6. Before fixes, IPv6 prefix rotation (e.g., /64) and multiple textual representations could produce 2^64 distinct keys, letting an attacker p...

CVE-2026-45364 Better Auth: Rate limiter keys IPv6 addresses individually and is bypassable via prefix rotation

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for or the configured IP-bearing header. IPv6 clients controlling a typical /6...

CVE-2026-45364 Better Auth: Rate limiter keys IPv6 addresses individually and is bypassable via prefix rotation

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for or the configured IP-bearing header. IPv6 clients controlling a typical /6...

Better Auth 安全漏洞

Better Auth is an open-source TypeScript framework for authentication. Versions of Better Auth prior to 1.4.17 and 1.5.0-beta.9 contained security vulnerabilities. These vulnerabilities stemmed from the HTTP rate limiter, which keyed each request based on the exact text IP address in the...

@altipla/directus-sdk-utils (=0.7.2), @better-auth/infra (>=0.1.7 <=0.1.8) +39 more potentially affected by CVE-2026-46490 via samlify (>=2.10.0 <=2.12.0)

samlify NPM version =2.10.0, =0.1.7, =1.6.0, =2.10.4, =1.0.0, =1.0.0, =11.16.1-depup.0, =27.1.0, =0.73.0, =0.0.0-chat-to-edit-20251124233201, =0.0.0-chat-to-edit-20251124233201, =0.75.0 and more Source cves: CVE-2026-46490 Source advisory: SNYK:JS-SAMLIFY-16796318...

@better-auth/cli (>=1.5.0-beta.10 <=1.5.0-beta.13), @onmax/nuxt-better-auth (>=0.0.2-alpha.14 <=0.0.2-alpha.32) +2 more potentially affected by CVE-2026-45364 via better-auth (>=1.5.0-beta.10 <=1.5.0-beta.20)

better-auth NPM version =1.5.0-beta.10, =1.5.0-beta.10, =0.0.2-alpha.14, =1.5.0-beta.15, =0.0.2-beta.19, =0.0.10-beta.25 Source cves: CVE-2026-45364 Source advisory: OSV:GHSA-P6V2-XCPG-H6XW...

@alstar/studio (=0.0.0-beta.20), @better-auth/cli (>=0.0.1 <=1.4.1-beta.1) +66 more potentially affected by CVE-2026-45364 via better-auth (>=0.4.10-beta.10 <=1.4.16)

better-auth NPM version =0.4.10-beta.10, =0.0.1, =1.3.27, =1.3.27, =1.3.27, =1.3.27, =1.3.27, =1.3.27, =1.3.26, =1.3.27, =0.18.0, =0.5.2, =1.0.2, =1.0.2, =1.0.2, =1.0.3 and more Source cves: CVE-2026-45364 Source advisory: OSV:GHSA-P6V2-XCPG-H6XW...

Better Auth: Rate limiter keys IPv6 addresses individually and is bypassable via prefix rotation

Am I affected? Users are affected if all of the following are true: - Their app uses better-auth at a version 1.4.17, or at a v1.5 prerelease tagged = 1.5.0-beta.8. - The apps authentication endpoints serve clients reachable over IPv6. Most managed hosts including Cloudflare, Vercel, Fly.io, AWS...

Cross-site Request Forgery (CSRF)

Overview better-auth is a The most comprehensive authentication library for TypeScript. Affected versions of this package are vulnerable to Cross-site Request Forgery CSRF when building an errorURL in parseGenericState, when the storeStateStrategy is set to "cookie" and PKCE is disabled. An...

NPM: Better Auth: OAuth callback accepts mismatched `state` when cookie-backed state storage is used without PKCE

NPM: Better Auth: OAuth callback accepts mismatched state when cookie-backed state storage is used without PKCE vulnerability discovered by ? in WordPress Npm better-auth versions 1.6.2...

9gen (>=0.0.23 <=0.1.1), @1sat/connect (>=0.0.15 <=0.0.68) +810 more potentially affected by unknown CVE via better-auth (>=0.4.10-beta.10 <=1.6.12)

better-auth NPM version =0.4.10-beta.10, =0.0.23, =0.0.15, =0.0.16, =0.0.1, =0.260505.5, =1.0.0, =0.6.1, =0.0.13, =0.3.3, =0.2.0, =0.0.110, =0.0.110, =0.1.41, =0.0.110, =2.0.0-beta.1 and more Source cves: unknown CVE Source advisory: OSV:GHSA-WXW3-Q3M9-C3JR...

9gen (>=0.0.23 <=0.1.1), @1sat/connect (>=0.0.15 <=0.0.68) +808 more potentially affected by unknown CVE via better-auth (>=1.0.0-canary.10 <=1.6.12)

better-auth NPM version =1.0.0-canary.10, =0.0.23, =0.0.15, =0.0.16, =0.0.1, =0.260505.5, =1.0.0, =0.6.1, =0.0.13, =0.3.3, =0.2.0, =0.0.110, =0.0.110, =0.1.41, =0.0.110, =2.0.0-beta.1 and more Source cves: unknown CVE Source advisory: SNYK:JS-BETTERAUTH-16722768...

Better Auth: OAuth callback accepts mismatched `state` when cookie-backed state storage is used without PKCE

Am I affected? Users are affected if all of the following are true: - The application uses better-auth at a version below 1.6.2 or @better-auth/sso paired with such a version. - betterAuth account: storeStateStrategy is set to "cookie". The default "database" is not affected. - The application...

PT-2026-41393

Name of the Vulnerable Software and Affected Versions Better Auth versions prior to 1.4.17 Better Auth versions prior to 1.5.0-beta.9 Description The HTTP rate limiter in Better Auth identifies requests based on the exact textual IP address found in the x-forwarded-for header or other configured...