What is CVE-2026-110021?

CVE-2026-110021 is a medium-severity vulnerability in Phoenix Contact Plcnext Engineer, classified under Improper Verification of Cryptographic Signature. CVSS score: 6.2/10. Published 2026-11-04.

How severe is CVE-2026-110021?

Medium severity. CVSS v3 base score is 6.2 out of 10.

Vulnerability in Phoenix Contact Plcnext Engineer

CVE-2026-110021

PLCnext Engineer checks GSDX manifest reference digests but does not cryptographically verify the XML `SignatureValue` over canonicalized `SignedInfo`. An unauthenticated local attacker can modify signed GSDML content, update its manifest digest, retain the public certificate data, and leave an invalid nonempty `SignatureValue`. PLCnext Engineer prior to 2026.6 reports the package as `Valid` and selects the modified device description for import under the default policy.

Published 2026-11-04 · last modified 2026-11-04.

CVSS v3 metric

CVSS v3 base score 6.2 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Phoenix Contact Plcnext Engineer

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

www.certvde.com/en/advisories/VDE-2026-121/

Frequently asked questions

What is CVE-2026-110021?: CVE-2026-110021 is a medium-severity vulnerability in Phoenix Contact Plcnext Engineer, classified under Improper Verification of Cryptographic Signature. CVSS score: 6.2/10. Published 2026-11-04.
How severe is CVE-2026-110021?: Medium severity. CVSS v3 base score is 6.2 out of 10.