CVE-2026-8741
EMQX QoS 2 PUBLISH Packet emqx_persistent_session_ds.erl race condition
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.
INFO
Published Date :
May 17, 2026, 9:16 a.m.
Last Modified :
May 20, 2026, 11:02 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 2.0 | LOW | [email protected] | ||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Update EMQX to version 6.2.1 or later.
- Review vendor security advisories for patches.
- Apply necessary security updates promptly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-8741.
| URL | Resource |
|---|---|
| https://github.com/Pathfind-tama/Report_EMQX_MQTT | Third Party Advisory |
| https://github.com/Pathfind-tama/Report_EMQX_MQTT/blob/main/MQTT%20QoS%202%20Message%20Duplication%20in%20Persistent%20Sessions.md | Third Party Advisory Exploit Mitigation |
| https://vuldb.com/submit/809931 | Third Party Advisory VDB Entry |
| https://vuldb.com/vuln/364329 | Third Party Advisory VDB Entry |
| https://vuldb.com/vuln/364329/cti | Permissions Required VDB Entry |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-8741 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-8741
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-8741 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-8741 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 20, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:emqx:emqx:*:*:*:*:*:*:*:* versions from (including) 5.0.0 up to (including) 6.2.0 Added Reference Type VulDB: https://github.com/Pathfind-tama/Report_EMQX_MQTT Types: Third Party Advisory Added Reference Type VulDB: https://github.com/Pathfind-tama/Report_EMQX_MQTT/blob/main/MQTT%20QoS%202%20Message%20Duplication%20in%20Persistent%20Sessions.md Types: Exploit, Mitigation, Third Party Advisory Added Reference Type VulDB: https://vuldb.com/submit/809931 Types: Third Party Advisory, VDB Entry Added Reference Type VulDB: https://vuldb.com/vuln/364329 Types: Third Party Advisory, VDB Entry Added Reference Type VulDB: https://vuldb.com/vuln/364329/cti Types: Permissions Required, VDB Entry -
New CVE Received by [email protected]
May. 17, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Added CVSS V2 (AV:N/AC:H/Au:S/C:N/I:N/A:P) Added CWE CWE-362 Added Reference https://github.com/Pathfind-tama/Report_EMQX_MQTT Added Reference https://github.com/Pathfind-tama/Report_EMQX_MQTT/blob/main/MQTT%20QoS%202%20Message%20Duplication%20in%20Persistent%20Sessions.md Added Reference https://vuldb.com/submit/809931 Added Reference https://vuldb.com/vuln/364329 Added Reference https://vuldb.com/vuln/364329/cti