CVE-2026-66074: rabbitmq-server · ReDoS
Affects rabbitmq-serverSource CVE Database V5
Not known to be exploited · CVSS 6.0 Medium · fixed in 4.2.6 : update rabbitmq-server when convenient.
Data as of 6 Nov 2026, 23:24 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.2.6, 4.1.11, 4.0.20 +1
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 23 Sep 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 6 Nov 2026.
What to do
Upgrade rabbitmq-server to 4.2.6, 4.1.11, 4.0.20 or 3.13.15.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| rabbitmqrabbitmq-server | Affected
| Fixed in
|
| rabbitmqrabbitmq-server | Affected
| Fixed in
|
| rabbitmqrabbitmq-server | Affected
| Fixed in
|
| rabbitmqrabbitmq-server | 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-server to version 3.13.15, 4.0.20, 4.1.11, 4.2.6, or later where this issue is fixed. No other mitigation is indicated or required as the fix addresses the root cause.
Description
RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, match_value/3 passes the user-supplied ?name= regular expression to re:run with no match_limit option, and executes it once per resource in the result set. OTP's default 10M match_limit caps each call at roughly 100-200ms, but the regex runs once per resource in the result set. With a large set, for example 5000 queues at 150ms each, a single request consumes 12 or more minutes of CPU. Parallel requests saturate the schedulers. The use_regex=true option is a supported feature on list endpoints, so this path is reachable through normal API use. Preconditions include Any user with the management tag can exploit this.. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.