# CVE-2026-110022: Signed plug-in validation bypass

Status: published. Published: 2026-11-04. Updated: 2026-11-04.

The PFI plugin framework deploys executable assemblies (DLLs) from a signed plugin package into the local plugin repository and loads them via reflection, but the deployment routine processes archive entries that were never covered by the signature verification. An unauthenticated local attacker can replace an unsigned DLL outside the signed prefix in the archive passes verification and overwrites the legitimate signed assembly at the same destination path. The plugin loader then instantiates the attacker-supplied code without any additional integrity check resulting in a full compromise of the affected systems.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Phoenix Contact / PLCnext Engineer: ≥ 0.0; < 2026.6 (affected, semver). Source: CNA: CERTVDE

## Severity and prioritization

- CVSS 4.0: 8.6 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: CERTVDE

- CVSS 3.1: 8.4 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H; source: CNA: CERTVDE

- CVSS 4.0: 8.6 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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: info@cert.vde.com

- CVSS 3.1: 8.4 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H; source: NVD: info@cert.vde.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-494

## Exploit evidence

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

## References

- https://www.certvde.com/en/advisories/VDE-2026-121/ (CNA: CERTVDE)

- https://www.certvde.com/en/advisories/VDE-2026-121/ (info@cert.vde.com)

## Provenance

- CNA: CERTVDE: https://www.cve.org/CVERecord?id=CVE-2026-110022; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-110022; retrieved 2026-11-04; source updated 2026-11-04

Revision: 388648fd57b58bb8d5661da6f28bdb53d1634534a09beb6ee084c5abce314bbb

Canonical: https://y2.dev/cve/CVE-2026-110022

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