Skip to content
EXYS
Back to the CVEs

CVE-2026-110863

8.1, high

Better-auth sso Improper Authentication Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
8.1, high high CVSS v3.1
EPSS, next 30 days
0.3% higher than 17.7% of scored CVEs
Exploitation
No public evidence
Published
14 Oct 20263 days ago

Description

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.

Details

Vendor
Better-auth
Product
sso
Weakness
CWE-287 (opens in a new tab)
Status
Awaiting analysis
Updated
15 Oct 2026
Assigner
disclosure@vulncheck.com

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References 2

Advisories 1

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Better-auth CVEs

Every Better-auth CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-110862 better-auth Improper Authentication Vulnerability EPSS 0.3% 9.1, critical
  • CVE-2026-110864 better-auth Improper Authentication Vulnerability EPSS 0.3% 7.4, high
  • CVE-2026-109346 better-auth from 1.3.8-beta.3 before 1.7.0-rc.3 contains a UI misrepresentation vulnerability in the deviceAuthorization plugin because… EPSS 0.3% 8.1, high

Beyond this page

Is CVE-2026-110863 in your network?

This page tells you how dangerous CVE-2026-110863 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

  • EXYS7600 OCELOT

    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2026-110863 comes with the devices to patch.

    Learn more about EXYS7600 OCELOT

  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

    Learn more about EXYS7950 KONDRA
Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.