CVE-2026-40946 — oxia
CVE-2026-40946 is a Improper Authentication vulnerability in github.com/oxia-db/oxia. A fix is available for github.com/oxia-db/oxia — see the affected versions and patch details below.
Oxia: OIDC token audience validation bypass via SkipClientIDCheck
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-40946.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/oxia-db/oxiaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The OIDC authentication provider unconditionally sets SkipClientIDCheck: true in the go-oidc verifier configuration, disabling the standard audience (aud) claim validation at the library level. This allows tokens issued for unrelated services by the same OIDC issuer to be accepted by Oxia.
Impact
In deployments using OIDC authentication, an attacker possessing a valid JWT token issued by the same identity provider but intended for a different service (different client_id/aud) can authenticate to Oxia. This bypasses the intended audience isolation of OAuth2/OIDC.
All versions using OIDC authentication are affected.
Details
In oxiad/common/rpc/auth/oidc.go, both createStaticKeyVerifier() and createRemoteVerifier() set SkipClientIDCheck: true. While a custom audience check exists in Authenticate(), the library-level check — which validates the aud claim against the expected client_id — is completely bypassed.
Patches
Fixed by removing SkipClientIDCheck: true and setting the ClientID field from the configured AllowedAudiences.
Workarounds
Ensure network-level isolation so that only trusted services can reach the Oxia gRPC endpoints.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/oxia-db/oxia | all versions | 0.16.2go get github.com/oxia-db/oxia@v0.16.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/oxia-db/oxia, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/oxia-db/oxia to 0.16.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40946 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-40946 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-40946. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-40946 in your dependencies?
O3 Security finds CVE-2026-40946 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.