CVE-2026-49998

Centrifugo: Dynamic JWKS key cache keyed only by `kid` allows cross-issuer JWT authentication bypass

HIGH
8.2
CVSS Score
Published: July 16, 2026 at 07:33 PM UTC
Updated: October 24, 2026 at 08:10 PM UTC
1 product affected across 1 vendorCentrifugo

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Severity
HIGH8.2
Exploit prediction
EPSS 0.2%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 6.8.1
Affected range stops below 6.8.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-347

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