---
title: "CVE-2026-53513: @better-auth/sso provider registration has server-side request forgery via unvalidated OIDC endpoints"
url: https://erroneo.us/security/cve/CVE-2026-53513/
description: "CVE-2026-53513 (@better-auth/sso (npm)): Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the @better-auth/sso…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-07-15
date_modified: 2026-07-20
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-53513"
kev: false
cvss: 9.6
epss: 0.00248
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-53513: @better-auth/sso provider registration has server-side request forgery via unvalidated OIDC endpoints

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.2% , percentile 15: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 15% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes @better-auth/sso (npm) >= 0.1.0, < 1.6.11, fixed in 1.6.11 . Check your lockfile, including transitive dependencies.

## What it is

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the @better-auth/sso plugin's POST /sso/register and POST /sso/update-provider endpoints accept attacker-controlled oidcConfig.userInfoEndpoint, tokenEndpoint, and jwksEndpoint URLs when skipDiscovery: true is set, store them on the ssoProvider row without origin validation, and fetch them during OIDC callback, allowing non-blind server-side request forgery and possible account linking when trustEmailVerified: true is configured. This issue is fixed in version 1.6.11.

## Affected packages

- npm `@better-auth/sso` >= 0.1.0, < 1.6.11 → fixed: 1.6.11

## Affected products (CVE record)

- better-auth better-auth: >= 0.1.0, < 1.6.11
- @better-auth sso: >= 0.1.0, < 1.6.11

## Severity

- GitHub_M CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.25% probability of exploitation activity in the next 30 days; percentile 15.

## Sources

- [GitHub Advisory GHSA-5rr4-8452-hf4v](https://github.com/advisories/GHSA-5rr4-8452-hf4v)
- [CVE.org record CVE-2026-53513](https://www.cve.org/CVERecord?id=CVE-2026-53513)
- [NVD entry CVE-2026-53513](https://nvd.nist.gov/vuln/detail/CVE-2026-53513)
- [github.com](https://github.com/better-auth/better-auth/security/advisories/GHSA-5rr4-8452-hf4v)
- [github.com](https://github.com/better-auth/better-auth/pull/9574)
- [github.com](https://github.com/better-auth/better-auth/commit/37f60cb176cb53147da7dfd5ec15afa5b486e81e)
- [github.com](https://github.com/better-auth/better-auth/releases/tag/v1.6.11)

---
Source page: https://erroneo.us/security/cve/CVE-2026-53513/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt