CVE-2026-124758

Integer underflow of the record data length in IODWrite requests

Published Nov 13, 2026 CVSS 4.0 · 2.3 Low EPSS n/a KEV · Not listed
Description
P-Net before 1.0.4 does not check the record data length of an IODWrite request to a non-user record index against the size of the record block header. The 32-bit length is reduced by the header size before it is passed to the record handlers, so a length smaller than the header underflows and the handlers receive a data length of about 65530. The fixed-size reads of the I&M and PDPort handlers can then read past the end of the session buffer. The result of the write is discarded. The attacker must have an established Application Relationship or be able to send in the context of one, and requires ADJACENT network access.

Analysis

No analysis available yet

Remediation

Vendor Solution

Upgrade to P-Net 1.0.4 or later.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Rt-labs
Rt-labs p-net
Vendors & Products Rt-labs
Rt-labs p-net
Type Values Removed Values Added
Description P-Net before 1.0.4 does not check the record data length of an IODWrite request to a non-user record index against the size of the record block header. The 32-bit length is reduced by the header size before it is passed to the record handlers, so a length smaller than the header underflows and the handlers receive a data length of about 65530. The fixed-size reads of the I&M and PDPort handlers can then read past the end of the session buffer. The result of the write is discarded. The attacker must have an established Application Relationship or be able to send in the context of one, and requires ADJACENT network access.
Title Integer underflow of the record data length in IODWrite requests
Weaknesses CWE-191
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Weaknesses
  • CWE-191

    Integer Underflow (Wrap or Wraparound)

Sources

Status
PUBLISHED
Assigner
rt-labs
Published
Updated
Nov 13, 2026, 1:23 PM
Reserved
Nov 9, 2026, 12:48 PM
Status
Deferred
Published
Nov 13, 2026, 2:17 PM
Modified
Nov 13, 2026, 2:17 PM