How severe is CVE-2026-41427?

CVE-2026-41427 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-41427 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-41427?

CVE-2026-41427 primarily affects Better-auth Better-auth/oauth-provider. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-41427?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-41427 have an EU (EUVD) identifier?

Yes. CVE-2026-41427 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25617.

When was CVE-2026-41427 published?

CVE-2026-41427 was published on 2026-04-24 and last updated on 2026-06-17.

CVE-2026-41427

CVE-2026-41427 is a medium-severity vulnerability in Better-auth Better-auth/oauth-provider with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 7.1
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-25617
Weakness: CWE-863
Affected product: Better-auth Better-auth/oauth-provider
Published: 2026-04-24
Last modified: 2026-06-17

Description

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.5, the clientPrivileges option documents a create action, but the OAuth client creation endpoints did not invoke the hook before persisting new clients. Deployments that configured clientPrivileges to restrict client registration were not actually restricted — any authenticated user could reach the create endpoints and register an OAuth client with attacker-chosen redirect URIs and metadata. This vulnerability is fixed in 1.6.5.

Frequently asked questions

What is CVE-2026-41427?: Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.5, the clientPrivileges option documents a create action, but the OAuth client creation endpoints did not invoke the hook before persisting new clients. Deployments that configured clientPrivileges to restrict client registration were not actually restricted — any authenticated user could reach the create endpoints and register an OAuth client with attacker-chosen redirect URIs and metadata. This vulnerability is fixed in 1.6.5.
How severe is CVE-2026-41427?: CVE-2026-41427 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-41427 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-41427?: CVE-2026-41427 primarily affects Better-auth Better-auth/oauth-provider. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-41427?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-41427 have an EU (EUVD) identifier?: Yes. CVE-2026-41427 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25617.
When was CVE-2026-41427 published?: CVE-2026-41427 was published on 2026-04-24 and last updated on 2026-06-17.

References

https://github.com/better-auth/better-auth/security/advisories/GHSA-xr8f-h2gw-9xh6

Affected products (4)

cpe:2.3:a:better-auth:better-auth\/oauth-provider:*:*:*:*:*:node.js:*:*
cpe:2.3:a:better-auth:better-auth\/oauth-provider:1.4.8:-:*:*:*:node.js:*:*
cpe:2.3:a:better-auth:better-auth\/oauth-provider:1.4.8:beta7:*:*:*:node.js:*:*
cpe:2.3:a:better-auth:better-auth\/oauth-provider:1.7.0:beta0:*:*:*:node.js:*:*

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