Vulnerability · Published Jul 16, 2026 · Assigned by GitHub_M
CVE-2026-49998Centrifugo: Dynamic JWKS key cache keyed only by `kid` allows cross-issuer JWT authentication bypass
High 8.2
In plain English
A high-severity security flaw in centrifugo from centrifugal. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Centrifugo is an open-source scalable real-time messaging server. Prior to 6.8.1, Centrifugo dynamic JWKS endpoint verification could reuse a key for one allowed issuer to verify a JWT for another allowed issuer because the JWKS cache and singleflight lookup were keyed only by JWT header kid, not by the resolved JWKS endpoint, issuer, audience, or trust-domain namespace, affecting client.token.jwks_public_endpoint, client.subscription_token.jwks_public_endpoint, internal/jwks/cache.go, and internal/jwks/manager.go. This issue is fixed in version 6.8.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/centrifugal/centrifugo | no fix listed | GHSA-g6vg-wj8f-48cj |
| Go | github.com/centrifugal/centrifugo | no fix listed | GO-2026-5872 |
| Go | github.com/centrifugal/centrifugo/v3 | no fix listed | GO-2026-5872 |
| Go | github.com/centrifugal/centrifugo/v3 | no fix listed | GHSA-g6vg-wj8f-48cj |
| Go | github.com/centrifugal/centrifugo/v4 | no fix listed | GO-2026-5872 |
| Go | github.com/centrifugal/centrifugo/v4 | no fix listed | GHSA-g6vg-wj8f-48cj |
| Go | github.com/centrifugal/centrifugo/v5 | no fix listed | GHSA-g6vg-wj8f-48cj |
| Go | github.com/centrifugal/centrifugo/v5 | no fix listed | GO-2026-5872 |
| Go | github.com/centrifugal/centrifugo/v6 | 6.8.1 | GO-2026-5872 |
| Go | github.com/centrifugal/centrifugo/v6 | 6.8.1 | GHSA-g6vg-wj8f-48cj |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| centrifugal | centrifugo | < 6.8.1 |
Weakness: CWE-347 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
References
- https://github.com/centrifugal/centrifugo/security/advisories/GHSA-g6vg-wj8f-48cj x_refsource_CONFIRM
- https://github.com/centrifugal/centrifugo/pull/1142 x_refsource_MISC
- https://github.com/centrifugal/centrifugo/commit/15d785015c6f318c1b68ea40b813699c9f8bd2c4 x_refsource_MISC
- https://github.com/centrifugal/centrifugo/releases/tag/v6.8.1 x_refsource_MISC