What is the CVSS score of CVE-2026-31813?

CVE-2026-31813 has a CVSS 3.1 base score of 4.8 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Microsoft are affected by CVE-2026-31813?

Organizations using Supabase Auth should be aware of moderate risk from CVE-2026-31813 rated CVSS 4.8. Exploitation could compromise the security of affected deployments.

How to fix or mitigate CVE-2026-31813?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Microsoft CVE-2026-31813

MEDIUM

Authentication Bypass by Spoofing (CWE-290)

2026-03-11 security-advisories@github.com

Microsoft Authentication Bypass Apple

4.8

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

4.8 MEDIUM

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

CVE Published

Mar 11, 2026 - 17:16 nvd

MEDIUM 4.8

DescriptionGitHub Advisory

Supabase Auth is a JWT based API for managing users and issuing JWT tokens. Prior to 2.185.0, a vulnerability has been identified that allows an attacker to issue sessions for arbitrary users using specially crafted ID tokens when the Apple or Azure providers are enabled. The attacker issues a valid, asymmetrically signed ID token from their issuer for each victim email address, which then is sent to the Supabase Auth token endpoint using the ID token flow. If the ID token is OIDC compliant, the Auth server would validate it against the attacker-controlled issuer and link the existing OIDC identity (Apple or Azure) of the victim to an additional OIDC identity based on the ID token contents. The Auth server would then issue a valid user session (access and refresh tokens) at the AAL1 level to the attacker. This vulnerability is fixed in 2.185.0.

AnalysisAI

Supabase Auth allows remote attackers to hijack user sessions by crafting fraudulent ID tokens when Apple or Azure OAuth providers are configured, enabling unauthorized access to victim accounts without requiring user interaction. An attacker can forge a valid JWT token for any target email address and exchange it at the token endpoint to obtain legitimate session credentials, effectively impersonating arbitrary users. This affects organizations using Supabase with Apple or Azure authentication enabled, with no patch currently available to remediate the vulnerability.

Technical ContextAI

This vulnerability (CWE-290: Authentication Bypass by Spoofing) affects Supabase Auth is a JWT based API for managing users and issuing JWT tokens.. Supabase Auth is a JWT based API for managing users and issuing JWT tokens. Prior to 2.185.0, a vulnerability has been identified that allows an attacker to issue sessions for arbitrary users using specially crafted ID tokens when the Apple or Azure providers are enabled. The attacker issues a valid, asymmetrically signed ID token from their issuer for each victim email address, which then is sent to the Supabase Auth token endpoint using the ID token flow. If the ID token is OIDC compliant, the