CVE-2026-40946Network attack vector

Authentication bypass via disabled OIDC audience validation

Published Apr 21, 2026 · Updated Apr 21, 2026

Authentication bypass in Oxia before 0.16.2 allows remote attackers to access the service with an OIDC token meant for another audience. The OIDC provider sets SkipClientIDCheck in both verifier constructors, preventing go-oidc from comparing the aud claim with the configured client ID. Exploitation requires OIDC authentication and a valid JWT from the same issuer for another client, which authenticates the token holder to reachable Oxia gRPC endpoints.

CVSS severity9.2
Critical
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Oxia before 0.16.2 allows remote attackers to access the service with an OIDC token meant for another audience. The OIDC provider sets SkipClientIDCheck in both verifier constructors, preventing go-oidc from comparing the aud claim with the configured client ID. Exploitation requires OIDC authentication and a valid JWT from the same issuer for another client, which authenticates the token holder to reachable Oxia gRPC endpoints.

The record

CVE
CVE-2026-40946
Published
Apr 21, 2026
Updated
Apr 21, 2026
Vendor
Oxia
Product
Oxia
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.16.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oxia · Oxiaversion=< 0.16.2

Published CVSS scores

9.2GitHub, Inc.CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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