3.7
LOW CVSS 3.1
CVE-2026-13491
78 xiaozhi-esp32 MQTT Goodbye mqtt_protocol.cc GetInstance denial of service
Description

A vulnerability was detected in 78 xiaozhi-esp32 up to 2.2.6. This vulnerability affects the function Application::GetInstance of the file main/protocols/mqtt_protocol.cc of the component MQTT Goodbye Handler. Performing a manipulation of the argument session_id results in denial of service. The attack is possible to be carried out remotely. The complexity of an attack is rather high. It is stated that the exploitability is difficult. The exploit is now public and may be used. The patch is named e182471f8c5a22434346bd98da34d3b66c8c8b3e. It is recommended to apply a patch to fix this issue.

INFO

Published Date :

June 28, 2026, 12:17 p.m.

Last Modified :

June 29, 2026, 6:43 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-13491 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 78 xiaozhi-esp32
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 2.0 LOW [email protected]
CVSS 3.1 LOW [email protected]
CVSS 4.0 LOW [email protected]
Solution
Apply the patch to fix the MQTT Goodbye Handler denial of service vulnerability.
  • Apply the provided patch e182471f8c5a22434346bd98da34d3b66c8c8b3e.
  • Update the 78 xiaozhi-esp32 firmware to version 2.2.7 or later.
  • Monitor network traffic for suspicious MQTT activity.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-13491 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-2026-13491 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-2026-13491 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-13491 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.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 29, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-13491', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-29T12:28:44.324743Z'}
  • New CVE Received by [email protected]

    Jun. 28, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:2.3:a:78:xiaozhi-esp32:*:*:*:*:*:*:*:*'], 'vendor': '78', 'modules': ['MQTT Goodbye Handler'], 'product': 'xiaozhi-esp32', 'versions': [{'status': 'affected', 'version': '2.2.0'}, {'status': 'affected', 'version': '2.2.1'}, {'status': 'affected', 'version': '2.2.2'}, {'status': 'affected', 'version': '2.2.3'}, {'status': 'affected', 'version': '2.2.4'}, {'status': 'affected', 'version': '2.2.5'}, {'status': 'affected', 'version': '2.2.6'}]}]
    Added Description A vulnerability was detected in 78 xiaozhi-esp32 up to 2.2.6. This vulnerability affects the function Application::GetInstance of the file main/protocols/mqtt_protocol.cc of the component MQTT Goodbye Handler. Performing a manipulation of the argument session_id results in denial of service. The attack is possible to be carried out remotely. The complexity of an attack is rather high. It is stated that the exploitability is difficult. The exploit is now public and may be used. The patch is named e182471f8c5a22434346bd98da34d3b66c8c8b3e. It is recommended to apply a patch to fix this issue.
    Added CVSS V4.0 AV:N/AC:H/AT:N/PR:N/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:N/UI:N/S:U/C:N/I:N/A:L
    Added CVSS V2 (AV:N/AC:H/Au:N/C:N/I:N/A:P)
    Added CWE CWE-404
    Added Reference https://github.com/78/xiaozhi-esp32/
    Added Reference https://github.com/78/xiaozhi-esp32/commit/e182471f8c5a22434346bd98da34d3b66c8c8b3e
    Added Reference https://github.com/78/xiaozhi-esp32/issues/2022
    Added Reference https://github.com/78/xiaozhi-esp32/pull/2023
    Added Reference https://vuldb.com/cve/CVE-2026-13491
    Added Reference https://vuldb.com/submit/838439
    Added Reference https://vuldb.com/vuln/374488
    Added Reference https://vuldb.com/vuln/374488/cti
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.