CVE-2026-127122: Memory Corruption

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.

Is your site exposed to CVE-2026-127122?

Run a free security scan — no signup, results in seconds.

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

References

Other References

https://rt-labs.com/wp-content/uploads/2026/11/RRTL-261109-01.pdf

Frequently Asked Questions

What is CVE-2026-127122? +

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.

How do I check if I'm vulnerable to CVE-2026-127122? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-8358

LibreOffice Calc can import tracked changes from a spreadsheet document. A heap buffer overflow existed when a document reused the …

CVE-2026-8356

LibreOffice can import presentations in the legacy binary PPT format. A stack buffer overflow existed when importing a colour-replacement record. …

CVE-2026-6040

A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the …

CVE-2026-6039

LibreOffice can import drawings in the DXF format used by CAD software. A heap buffer overflow existed when importing a …

CVE-2026-3298

The method "sock_recvfrom_into()" of "asyncio.ProacterEventLoop" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. …

CVE-2026-40489

editorconfig-core-c is an EditorConfig core library for use by plugins supporting EditorConfig parsing. Versions up to and including 0.12.10 have …