CVE-2026-31813 | Supabase Auth has insecure Apple and Azure authentication with ID 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 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.

Published: 2026-03-11 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-31813 is rated Low Risk (20.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.14%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-31813

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.14% +0.11%
2 2026-03-12 0.03%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-31813

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.2 2.5 [email protected]
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.2 2.5 [email protected]

Weakness enumeration for CVE-2026-31813

Affected software / configurations for CVE-2026-31813

Vendor Product Version Raw CPE
supabase auth < 2.185.0 cpe:2.3:a:supabase:auth:*:*:*:*:*:*:*:*

References for CVE-2026-31813

cvelogic Threat Intelligence