EMQX up to 6.2.0 QoS 2 PUBLISH Packet emqx_persistent_session_ds.erl race condition

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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2.9$0-$5k0.00

Summaryinfo

A vulnerability was found in EMQX up to 6.2.0. It has been rated as problematic. This impacts an unknown function of the file apps/emqx/src/emqx_persistent_session_ds.erl of the component QoS 2 PUBLISH Packet Handler. Performing a manipulation results in race condition. This vulnerability is cataloged as CVE-2026-8741. It is possible to initiate the attack remotely. Furthermore, there is an exploit available. The vendor was contacted early about this disclosure.

Detailsinfo

A vulnerability classified as problematic 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. The manipulation with an unknown input leads to a race condition vulnerability. CWE is classifying the issue as CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. This is going to have an impact on availability.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-8741. The exploitability is told to be difficult. It is possible to initiate the attack remotely. Technical details and a public exploit are known.

The exploit is shared for download at github.com. It is declared as proof-of-concept. The vendor was contacted early about this disclosure.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-30692). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 3.1
VulDB Meta Temp Score: 2.9

VulDB Base Score: 3.1
VulDB Temp Score: 2.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 3.1
CNA Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/16/2026 Advisory disclosed
05/16/2026 +0 days VulDB entry created
05/21/2026 +5 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Not defined

CVE: CVE-2026-8741 (🔒)
GCVE (CVE): GCVE-0-2026-8741
GCVE (VulDB): GCVE-100-364329
EUVD: 🔒
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 05/16/2026 13:24
Updated: 05/21/2026 14:33
Changes: 05/16/2026 13:24 (55), 05/17/2026 13:07 (1), 05/21/2026 14:33 (31)
Complete: 🔍
Submitter: CCCaaa
Cache ID: 216::103

Submitinfo

Accepted

  • Submit #809931: EMQX EMQX Broker EMQX 6.1.0 (confirmed) Race Condition (by CCCaaa)

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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