CVE-2026-44838: rabbitmq-server · Incorrect Authorization
Affects rabbitmq-serverSource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium : upgrade to 4.2.4 when convenient.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.2.4
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:H/SI:H/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade rabbitmq-server and rabbitmq/rabbitmq-server to 4.2.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| rabbitmqrabbitmq-server | Affected
| Fixed in
|
GitHubrabbitmq/rabbitmq-serverpkg:github/rabbitmq/rabbitmq-serverOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade RabbitMQ to version 4.2.4 or later, or 4.3.0 and above, where this vulnerability is fixed. Since the vulnerability is addressed in these versions, applying the official patch is the recommended remediation. Patch status is confirmed by the vendor advisory stating the fix is included in 4.2.4 and 4.3.0. No other mitigations are indicated.
Description
CVE-2026-44838 is a medium severity vulnerability in RabbitMQ's MQTT plugin versions 4.2.0 up to but not including 4.2.4. It involves incorrect authorization due to improper handling of user-supplied client_id values in topic-level authorization regex patterns. Because the client_id is inserted into regex patterns without escaping special characters, an authenticated MQTT user can inject regex operators to bypass topic access restrictions. This flaw is fixed in RabbitMQ versions 4.2.4 and 4.