better-auth up to 1.7.2 SSO providerId improper authentication

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$0-$5k0.40

Summaryinfo

A vulnerability was found in better-auth up to 1.7.2. It has been classified as critical. This affects an unknown function of the component SSO. This manipulation of the argument providerId causes improper authentication. The identification of this vulnerability is CVE-2026-110863. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in better-auth up to 1.7.2 and classified as critical. Affected by this vulnerability is an unknown code block of the component SSO. The manipulation of the argument providerId with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Better Auth @better-auth/sso from 1.7.0-rc.2 before 1.7.3 contains an authentication bypass vulnerability that allows authenticated users to sign in as other users by registering a personal SSO provider. Attackers can copy a legitimate provider's OIDC issuer or SAML entity ID and assert a victim's subject or NameID, because account lookup ignores providerId, creating sessions for victim accounts.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-110863 since 10/15/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 1.7.3 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.2
VulDB Meta Temp Score: 7.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.1
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: better-auth 1.7.3

Timelineinfo

10/14/2026 VulDB entry created
10/15/2026 +0 days Advisory disclosed
10/15/2026 +0 days CVE reserved
10/15/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-110863 (🔒)
GCVE (CVE): GCVE-0-2026-110863
GCVE (VulDB): GCVE-100-420439

Entryinfo

Created: 10/15/2026 01:27
Changes: 10/15/2026 01:27 (76)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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