CVE-2026-127122

Description

P-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.

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

• 7.2CVSS 4.0, Highfrom the CNA (rt-labs)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

What to do

• Upgrade to P-Net 1.0.4 or later.CNA solution statement
• 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.CNA workaround statement

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Timeline

1. 13 Nov 2026 Published

Weakness

• CWE-787

References

• Cybersecurity advisory for P-Net