CVE-2026-53515: Better Auth is an authentication and authorization library for TypeScript

Q: How do I fix CVE-2026-53515?

better-auth\/sso: upgrade to 1.6.11; better auth: upgrade to 1.6.11. Exact commands for each OS are on this page.

Q: Is CVE-2026-53515 being exploited?

CVE-2026-53515 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-53515 affect?

CVE-2026-53515 affects better-auth\/sso, better auth. Severity is high (CVSS 7.1). 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 becau

Routine

HIGH 7.1UPGRADEUPGRADE

CVE-2026-53515 is a high-severity flaw (CVSS 7.1) affecting better-auth\/sso, better auth. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 provisio

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 63%)
CISA exploited list	No
Weakness	CWE-269, CWE-285, CWE-863
Published	2026-07-15
Last modified	2026-07-21

Publisher (CNA): GitHub, Inc. · Vendor: better-auth

Last updated 2026-07-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-15 18:16 UTCPublished CVE record published
2026-07-21 15:38 UTCUpdated Record last modified

better-auth better-auth\/sso UPGRADE

Affected: < 1.6.11

Fixed in: 1.6.11

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls better-authsso

2. UPGRADE to 1.6.11

npm install better-authsso@">=1.6.11"

better-auth better auth UPGRADE

Affected: >= 1.2.10 and < 1.6.11

Fixed in: 1.6.11

Safe to downgrade to: a release before 1.2.10

1. Check installed version

npm ls better-auth

2. UPGRADE to 1.6.11

npm install better-auth@">=1.6.11"

3. If no update is available yet, DOWNGRADE to a release before 1.2.10

npm view better-auth versions npm install better-auth@"<1.2.10"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-53515?

better-auth\/sso: upgrade to 1.6.11; better auth: upgrade to 1.6.11. Exact commands for each OS are on this page.

Is CVE-2026-53515 being exploited?

CVE-2026-53515 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-53515 affect?

CVE-2026-53515 affects better-auth\/sso, better auth. Severity is high (CVSS 7.1). 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 becau

How urgent is CVE-2026-53515?

Priority 34/100. High severity

Related CVEs

CVE-2026-53513 CRITICAL 9.6 UPGRADE UPGRADE Better Auth is an authentication and authorization library for TypeScript

References

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