CVE-2026-67242

RabbitMQ: OAuth2 is_integer(Exp) guard skips token-expiry checks for float exp

MEDIUM
5.4
CVSS Score
Published: September 25, 2026 at 04:16 PM UTC
Updated: October 16, 2026 at 04:22 PM UTC
2 products affected across 2 vendorsRabbitmq ServerRabbitmq Server

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Severity
MEDIUM5.4
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.2.9 and 4.3.3, OAuth2 isinteger(Exp) guard skips token-expiry checks for float exp. validatetokenexpiry/1 (lines 208-214) and expirytimestamp/1 (138-144) both guard with 'when isinteger(Exp)' and fall through to ok/never for float values. josejwt:verify validates only the signature, not exp. With float exp, no expiry validation occurs anywhere in the If the IdP emits exp as a JSON float (RFC 7519 permits fractional NumericDate), both the login-time expiry check and the mid-connection disconnect timer are silently skipped , an already-expired token is accepted, and connections never time OAuth2 backend enabled IdP emits float exp (uncommon; mainstream IdPs emit integers) Attacker possesses a previously-valid signed. This issue is fixed in versions 4.2.9 and 4.3.3.

Affected

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

4.2.0 ≤ v < 4.2.94.3.0 ≤ v < 4.3.3
Affected range stops below 4.2.9, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.3.3, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

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

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-613

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