Vulnerability · Published Sep 25, 2026 · Assigned by GitHub_M
CVE-2026-67242RabbitMQ: OAuth2 is_integer(Exp) guard skips token-expiry checks for float exp
Medium 6.3
In plain English
A medium-severity security flaw in rabbitmq-server from rabbitmq. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | rabbitmq-server | 4.3.6-1 | DEBIAN-CVE-2026-67242 |
| Ubuntu:22.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67242 |
| Ubuntu:24.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67242 |
| Ubuntu:26.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67242 |
| Ubuntu:26.10 | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67242 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| rabbitmq | rabbitmq-server | >= 4.2.0, < 4.2.9>= 4.3.0, < 4.3.3 |
Weakness: CWE-613 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-rrj4-g94f-rqj9 x_refsource_CONFIRM
- https://github.com/rabbitmq/rabbitmq-server/commit/d10a369a96658d0fba1050bd43c732e58fcf28fd x_refsource_MISC
- https://github.com/rabbitmq/rabbitmq-server/commit/f189a8824c9efbce46bd9438fcdbda4521cfc923 x_refsource_MISC
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9 x_refsource_MISC
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3 x_refsource_MISC