CVE-2026-110021: Signature Bypass (CVSS 6.2)

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.

Is your site exposed to CVE-2026-110021?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.2

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS — Exploit Prediction

0.0006

Probability of exploitation

0.00%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-347 CWE-347

References

Other References

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

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 6.2 (MEDIUM).

How severe is CVE-2026-110021? +

CVE-2026-110021 has a CVSS v3.1 score of 6.2 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0006, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-110021? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-46684

DataEase is an open source data visualization and analysis tool. Prior to 2.10.23, DataEase enterprise token handling can let TokenFilter#doFilter() …

CVE-2026-67278

MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures during X.509 validation. Because its trust store includes an e=3 root CA, an …

CVE-2026-59639

In Bouncy Castle for Java before 1.85, CMS verifySignatures returns true for SignedData with zero signers. This issue also affects …

CVE-2026-12860

In Bouncy Castle for Java before 1.85, RSA PKCS#1 verification skips last two hash bytes in NULL-omitted path. This issue …

CVE-2026-44720

OpenLearnX is an open-source, decentralized learning and assessment platform. Prior to 2.0.4, a critical authentication vulnerability was identified in OpenLearnX …

CVE-2025-24800

Hyperbridge is a hyper-scalable coprocessor for verifiable, cross-chain interoperability. A critical vulnerability was discovered in the ismp-grandpa crate, that allowed …