Vulnerability · Published Nov 4, 2026 · Assigned by CERTVDE

CVE-2026-110021Missing GSDX SignatureValue verification

Medium 6.2

In plain English

A medium-severity security flaw in PLCnext Engineer from Phoenix Contact. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 0% of all known vulnerabilities).

Severity (CVSS 3.1)6.2Medium

Exploit odds (30 days)<0.1%top 100.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
Phoenix Contact	PLCnext Engineer	0.0 – before 2026.6

Weakness: CWE-347 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

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