# CVE-2026-127124: RPC session pool exhausted by unfinished fragmented requests

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

P-Net before 1.0.4 keeps the RPC session that is allocated for a fragment of a request with an unknown activity UUID, without a timeout, when the rest of the request never arrives. A session that does not get an Application Relationship is also kept after the response. Repeated fragments or requests with different activity UUIDs exhaust the available sessions, one UDP packet per session. Once they are exhausted the device no longer answers a Connect request until it is restarted. An unauthenticated attacker with ADJACENT network access can use this to cause a denial of service.

## Remediation

- fix: Upgrade to P-Net 1.0.4 or later. (source: CNA: rt-labs)

## Affected products and versions

- RT-Labs / P-Net: ≥ 0; < 1.0.4 (affected, semver). Source: CNA: rt-labs

## Severity and prioritization

- CVSS 4.0: 7.1 (high); CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N; source: CNA: rt-labs

- CVSS 4.0: 7.1 (high); CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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; source: NVD: 4b71179a-3b92-4a9d-b9fc-af8b8ed579ee

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-772

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

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

- https://rt-labs.com/wp-content/uploads/2026/11/RRTL-261109-01.pdf (4b71179a-3b92-4a9d-b9fc-af8b8ed579ee)

## Provenance

- CNA: rt-labs: https://www.cve.org/CVERecord?id=CVE-2026-127124; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-127124; retrieved 2026-11-13; source updated 2026-11-13

Revision: e7d3422e181d5bae0280361da5c4d6ebabfbb4fd2750b512dc85112d844cd5ad

Canonical: https://y2.dev/cve/CVE-2026-127124

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