---
id: CVE-2026-66349
title: |-
  The MMS server connection handler contains a flaw in its processing of 
  BER-encoded request data
summary: |-
  The MMS server connection handler contains a flaw in its processing of 
  BER-encoded request data. When an MMS confirmed request PDU containing 
  an extended BER tag is received over an established session, the decoder
   may advance its int…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-125
published: '2026-07-30'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T19:30:43.093'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-66349'
references:
  - url: >-
      https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-10.json
    label: ics-cert@hq.dhs.gov
  - url: 'https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-10'
    label: ics-cert@hq.dhs.gov
tags:
  - nvd
epss: 0.00295
epssPercentile: 0.19648
ingestedAt: '2026-09-08T20:10:03.155Z'
---

## Overview

The MMS server connection handler contains a flaw in its processing of 
BER-encoded request data. When an MMS confirmed request PDU containing 
an extended BER tag is received over an established session, the decoder
 may advance its internal buffer incorrectly due to a missing bounds 
check. This results in a one byte heap out-of-bounds read and causes the
 MMS service process to terminate, leading to a denial-of-service 
condition.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.