CVE-2026-65421

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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector ADJACENT_NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
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

Configurations

No configuration.

History

23 Oct 2026, 23:10

Type	Values Removed	Values Added
Summary		(es) El decodificador BER de MMS contiene una falla al decodificar campos BER de ancho fijo (booleano/entero): un valor de longitud proporcionado por el atacante no se valida, lo que causa una lectura más allá del final de un búfer de montón. Esto lleva a la terminación del proceso del servicio MMS y a una condición de denegación de servicio.

Information

Published : 2026-07-30 23:16

Updated : 2026-10-23 23:10

NVD link : CVE-2026-65421

Mitre link : CVE-2026-65421

CVE.ORG link : CVE-2026-65421

JSON object : View

Products Affected

No product.

CWE

CWE-125

Out-of-bounds Read

{"id": "CVE-2026-65421", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-65421", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-31T15:55:24.858279Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "ics-cert@hq.dhs.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 2.8}], "cvssMetricV40": [{"type": "Secondary", "source": "ics-cert@hq.dhs.gov", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 7.1, "Automatable": "NOT_DEFINED", "attackVector": "ADJACENT", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "ics-cert@hq.dhs.gov", "affectedData": [{"vendor": "MZ Automation GmbH", "product": "libiec61850", "versions": [{"status": "affected", "version": "0", "lessThan": "1.6.2", "versionType": "custom"}, {"status": "unaffected", "version": "1.6.2"}], "defaultStatus": "unaffected"}]}], "published": "2026-07-30T23:16:52.597", "references": [{"url": "https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-10.json", "source": "ics-cert@hq.dhs.gov"}, {"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-10", "source": "ics-cert@hq.dhs.gov"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "ics-cert@hq.dhs.gov", "description": [{"lang": "en", "value": "CWE-125"}]}], "descriptions": [{"lang": "en", "value": "The MMS BER decoder contains a flaw in decoding fixed-width BER fields \n(boolean/integer): an attacker-supplied length value is not validated, \ncausing a read past the end of a heap buffer. This leads to termination \nof the MMS service process and a denial-of-service condition."}, {"lang": "es", "value": "El decodificador BER de MMS contiene una falla al decodificar campos BER de ancho fijo (booleano/entero): un valor de longitud proporcionado por el atacante no se valida, lo que causa una lectura m\u00e1s all\u00e1 del final de un b\u00fafer de mont\u00f3n. Esto lleva a la terminaci\u00f3n del proceso del servicio MMS y a una condici\u00f3n de denegaci\u00f3n de servicio."}], "lastModified": "2026-10-23T23:10:00.157", "sourceIdentifier": "ics-cert@hq.dhs.gov"}