CVE-2026-65421

EUVD-2026-51342
The MMS BER decoder contains a flaw in decoding fixed-width BER fields 
(boolean/integer): an attacker-supplied length value is not validated, 
causing a read past the end of a heap buffer. This leads to termination 
of the MMS service process and a denial-of-service condition.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
icscertCNA
6.5 MEDIUM
ADJACENT_NETWORK
LOW
NONE
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 7%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mz-automationlibiec61850
𝑥
< 1.6.2
CNA
Common Weakness Enumeration
References
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-10.json
https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-10