CVE-2026-67418
MEDIUM 5.3RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5, the MQTT 5 parser in deps/rabbitmq_mqtt/src/rabbit_mqtt_packet.erl accepts Request-Problem-Information on PUBLISH packets even though the property is valid only for CONNECT. An authenticated publisher with topic write permission can cause the broker to store and route that inapplicable property to a separately authenticated matching subscriber. When the subscriber path serializes the outbound PUBLISH, serialise_prop/2 has no matching clause, and the uncontained function_clause exception closes the victim MQTT or Web MQTT connection. The publisher connection and broker remain available, and queued replay, retained-message persistence, and broker-wide denial of service were not established. This issue is fixed in versions 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 33rd percentile
Impact if exploited
5.3CVSS 4.0 · MEDIUM
- ConfidentialityNone
- IntegrityNone
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-67418/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-67418/poc.json
Weakness (CWE)
- CWE-1286: : Improper Validation of Syntactic Correctness of Input
- CWE-248: : Uncaught Exception
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
All CVSS metrics
- MEDIUM 5.3 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - MEDIUM 5.3 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
References
Technical & other
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-jv99-v328-mvmm
- https://github.com/rabbitmq/rabbitmq-server/pull/17035
- https://github.com/rabbitmq/rabbitmq-server/pull/17287
- https://github.com/rabbitmq/rabbitmq-server/commit/4639a4318c72a0660e4bc014767fad70ce288fbc
- https://github.com/rabbitmq/rabbitmq-server/commit/908f944a1d581d10774f8d6d0dcf2a1a713779fb
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5