Out-of-bounds write with too many MCR blocks in a Connect request

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-127122
StatePUBLISHED
Assignerrt-labs
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-13 14:17:54 UTC
Updated2026-11-13 20:18:50 UTC
DescriptionP-Net before 1.0.4 does not check the number of MCR request blocks in a Connect request against the number of multicast communication relations that an Application Relationship has room for (PNET_MAX_MC_CR, 1 by default). Each further block is written past the end of the array, into the rest of the Application Relationship and, with more blocks, into the following one. The written data comes from the request. No established Application Relationship is needed, and the attacker requires ADJACENT network access. Builds with PNET_OPTION_MC_CR disabled are not affected.

Risk And Classification

Primary CVSS: v4.0 7.2 HIGH from 4b71179a-3b92-4a9d-b9fc-af8b8ed579ee

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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

Problem Types: CWE-787 | CWE-787 CWE-787 Out-of-bounds Write

VersionSourceTypeScoreSeverityVector
4.04b71179a-3b92-4a9d-b9fc-af8b8ed579eeSecondary7.2HIGHCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS7.2HIGHCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Adjacent
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
Low
Integrity
Low
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA RT-Labs P-Net affected 1.0.4 semver Not specified

References

ReferenceSourceLinkTags
rt-labs.com/wp-content/uploads/2026/11/RRTL-261109-01.pdf 4b71179a-3b92-4a9d-b9fc-af8b8ed579ee rt-labs.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Solutions

CNA: Upgrade to P-Net 1.0.4 or later.

Workarounds

CNA: Build P-Net with PNET_OPTION_MC_CR disabled. Multicast communication relations are not supported by P-Net, and a Connect request with MCR blocks is then rejected.

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