Vulnerability in Emqx
CVE-2026-8741
A vulnerability has been found in EMQX up to 6.2.0. This affects an unknown function of the file apps/emqx/src/emqx_persistent_session_ds.erl of the component QoS 2 PUBLISH Packet Handler. Such manipulation leads to race condition. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is reported as difficult. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure.
Vulnerability class: Race Condition
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.004 (30.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Emqx
- Emqx — versions 6.0, 6.1, 6.2.0
Weakness classification (CWE)
References
- vuldb.com/vuln/364329 (VDB Entry, Third Party Advisory, vdb-entry)
- vuldb.com/vuln/364329/cti (signature, Permissions Required, permissions-required, VDB Entry)
- vuldb.com/submit/809931 (VDB Entry, Third Party Advisory, third-party-advisory)
- github.com/Pathfind-tama/Report_EMQX_MQTT (related, Third Party Advisory)
- github.com/Pathfind-tama/Report_EMQX_MQTT/blob/main/MQTT QoS 2 Message Duplicat… (Exploit, Third Party Advisory, exploit, Mitigation)
Frequently asked questions
- What is CVE-2026-8741?
- CVE-2026-8741 is a low-severity vulnerability in Emqx, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 3.1/10. Published 2026-05-17.
- How severe is CVE-2026-8741?
- Low severity. CVSS v3 base score is 3.1 out of 10.