Vulnerability record · CVE-2026-67419 · published 25 September 2026
CVE-2026-67419: Inefficient regular expression (ReDoS) vulnerability
RabbitMQ is a messaging and streaming broker. Prior to 4.3.5, an authenticated user who can bind a queue to a topic exchange and publish to it can use consecutive # segments in a binding key to make both topic matchers revisit the same trie-node and routing-key-suffix states without memoization. The matcher materializes duplicate destinations before deduplication, causing combinatorial CPU work and memory pressure that can disrupt routing for all tenants. This vulnerability is fixed in 4.3.5.
Description
RabbitMQ is a messaging and streaming broker. Prior to 4.3.5, an authenticated user who can bind a queue to a topic exchange and publish to it can use consecutive # segments in a binding key to make both topic matchers revisit the same trie-node and routing-key-suffix states without memoization. The matcher materializes duplicate destinations before deduplication, causing combinatorial CPU work and memory pressure that can disrupt routing for all tenants. This vulnerability is fixed in 4.3.5.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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:
References
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Source: NIST National Vulnerability Database (record CVE-2026-67419), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.
