EMQX QoS 2 PUBLISH Packet emqx_persistent_session_ds.erl race condition
Published May 17, 2026
2.3
LOWCVSS 4.0
EPSS 0.39%
Description
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.
Affected products
-
- Version 6.0StatusaffectedConstraints-
- Version 6.1StatusaffectedConstraints-
- Version 6.2.0StatusaffectedConstraints-
- Version
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
1 other source (NVD) ▾
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
AV:N/AC:H/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR
1 other source (NVD) ▾
AV:N/AC:H/Au:S/C:N/I:N/A:P
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed May 18, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
May–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 0.39% (0.00390) | 30.71th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.28% (0.00282) | 19.71th | v5 (v2026.06.15) |
| May 17, 2026 | 0.04% (0.00036) | 10.66th | v4 (v2025.03.14) |
References (5)
- https://github.com/Pathfind-tama/Report_EMQX_MQTT relatedThird Party Advisory
- https://github.com/Pathfind-tama/Report_EMQX_MQTT/blob/main/MQTT%20QoS%202%20Message%20Duplication%20in%20Persistent%20Sessions.md exploitMitigationThird Party Advisory
- https://vuldb.com/submit/809931 third-party-advisoryThird Party AdvisoryVDB Entry
- https://vuldb.com/vuln/364329 vdb-entryThird Party AdvisoryVDB Entry
- https://vuldb.com/vuln/364329/cti signaturepermissions-requiredPermissions RequiredVDB Entry
| Link | Providers | Tags |
|---|---|---|
| https://github.com/Pathfind-tama/Report_EMQX_MQTT | relatedThird Party Advisory | |
| https://github.com/Pathfind-tama/Report_EMQX_MQTT/blob/main/MQTT%20QoS%202%20Message%20Duplication%20in%20Persistent%20Sessions.md | exploitMitigationThird Party Advisory | |
| https://vuldb.com/submit/809931 | third-party-advisoryThird Party AdvisoryVDB Entry | |
| https://vuldb.com/vuln/364329 | vdb-entryThird Party AdvisoryVDB Entry | |
| https://vuldb.com/vuln/364329/cti | signaturepermissions-requiredPermissions RequiredVDB Entry |
Change history (0)
No recorded changes yet.