RT-Labs P-Net: NULL pointer dereference in implicit read handling
Summary
P-Net before 1.0.3, a PROFINET device stack used in industrial I/O devices, dereferences a NULL AR pointer when it handles an implicit read request without a valid AR UUID for a user specific record index. This happens only if the application has registered a read callback. A remote unauthenticated attacker who can reach the device can send such a request and crash it, causing a denial of service. The CVSS 8.7 score is the CNA's; NVD analysis is still pending.
Affected
- RT-Labs P-Net versions before 1.0.3 (per the CNA record; some sources state up to 1.0.2)
- Downstream devices that embed P-Net: unknown; vendors must confirm their firmware versions
Fixed in
- Upgrade to P-Net 1.0.3 or later (RT-Labs advisory RRTL-261019-01)
Workaround
Unknown.
Exploitation
- No evidence of exploitation in the wild found.
- No public proof of concept found.
- NVD status: Deferred.
Our recommendation
- Ask OT and device vendors whether their products embed P-Net and which version.
- Have vendors deliver the P-Net 1.0.3 update through firmware; do not patch the library directly.
- Segment PROFINET and OT networks from office IT.
- Check related RT-Labs P-Net flaws (CVE-2025-32398, CVE-2026-111733, CVE-2026-111731) together when updating.
- Re-check NVD and the RT-Labs advisory, as the NVD record is still pending.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- RT-Labs advisory RRTL-261019-01 rt-labs.com
- VulDB entry 428596 vuldb.com
- Strix AI CVE-2026-111736 www.strix.ai
- ThreatInt CVE record cve.threatint.com
- CVE Brief archive 2026/10/30 cvebrief.com
- Nozomi Networks advisory CVE-2025-32398 www.nozominetworks.com
- RT-Labs P-Net on GitHub github.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 23:40.
Original description (NVD)
P-Net before 1.0.3 dereferences a NULL AR pointer in pf_fspm_cm_read_ind() when handling an implicit read request without a valid target AR UUID for a user specific record index, if the application has registered a read callback. A remote unauthenticated attacker can send such a request to crash the device (denial of service).
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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