# CVE-2026-53515: Better Auth: Privilege escalation via SSO provider registration: missing admin role check in @better-auth/sso

> Attackers can register malicious SSO providers to escalate privileges and take over accounts due to missing admin role checks in the Better Auth SSO plugin.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Jul 2026
- **Updated:** 15 Jul 2026
- **Also known as:** GHSA-gv74-j8m3-fg5f

## What is CVE-2026-53515?

CVE-2026-53515 is a high-severity vulnerability in @better-auth better-auth, published on 15 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Better Auth is an authentication and authorization library for TypeScript. From 1.2.10 until 1.6.11, the @better-auth/sso plugin's POST /sso/register endpoint lets any organization member attach a new SSO provider to that organization because registerSSOProvider checks only for a membership row and does not require an owner or admin role, allowing attacker-controlled OIDC or SAML providers to drive /sso/callback/{providerId} organization provisioning. This issue is fixed in version 1.6.11.

Weakness: CWE-863 (Incorrect Authorization), CWE-285 (Improper Authorization), CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2026-53515?

2 open source packages ship an affected version, including @better-auth/sso. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@better-auth/sso` | npm | From 1.2.10 | 1.6.11 |
| `@better-auth/sso` | npm | From 1.2.10 | 1.6.11 |

Products: Better-Auth Better-Auth\/Sso, Better-Auth Better Auth.

## How do I fix CVE-2026-53515?

Upgrade @better-auth/sso to 1.6.11 or later.

## Is CVE-2026-53515 being exploited?

There is no known exploitation of CVE-2026-53515 in the wild and no public exploit code.

## Other vulnerabilities in @better-auth better-auth

- [CVE-2026-53513](https://insights.sbomify.com/CVE-2026-53513/): Better Auth: Server-side request forgery via unvalidated OIDC endpoints on @better-auth/sso provider registration (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53515 and fix it if it is affected.

What it is: CVE-2026-53515 is a high-severity vulnerability in @better-auth better-auth, published on 15 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53515 in the wild and no public exploit code.

Affected packages and fixed versions:
- @better-auth/sso (npm): affected from 1.2.10; fixed in 1.6.11
- @better-auth/sso (npm): affected from 1.2.10; fixed in 1.6.11

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53515/ (Markdown: https://insights.sbomify.com/CVE-2026-53515/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53515
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53515
- OSV: https://osv.dev/vulnerability/CVE-2026-53515

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53515/
Summaries are generated and may contain mistakes; the official description above is the record.