Apache PLC4X: OPC UA secure channel: integrity bypass, unverifiable server certificate, and silent downgrade
Improper Verification of Cryptographic Signature and Improper Certificate Validation in the OPC UA driver of Apache PLC4X (PLC4J) allows an attacker in a network position between client and server to impersonate the OPC UA server and to read, forge or modify secure-channel traffic, including user credential ssent by the client. The defect manifests differently depending on the version: - In 0.9.0 through 0.11.0 a failed message-signature check is only logged and never enforced, and there is no mechanism to verify the server certificate: it is taken from the unauthenticated GetEndpoints discovery response and used to encrypt the user's password. - In 0.12.0 through 0.13.1 the signature check is inverted (valid signatures are rejected, invalid ones accepted), and server certificates are accepted without a trust anchor by default. - In all affected versions the default security policy is None. Starting with 0.12.0 the driver additionally continues silently at a weaker security policy than the one configured, and starting with 0.13.0 endpoint selection prefers the weakest matching endpoint. Users checking only for one of these mechanisms may wrongly conclude they are unaffected. This issue affects Apache PLC4X: from 0.9.0 before 1.0.0. Users are recommended to upgrade to version 1.0.0, which fixes the issue. Version 1.0.0 verifies message signatures correctly, refuses to connect unless the server certificate can be verified against a configured trust store or pinned certificate,
CVE-2026-102508
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-102508
Apache PLC4X
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "Apache Software Foundation",
"product": "Apache PLC4X",
"versions": [
{
"status": "affected",
"version": "0.9.0",
"lessThan": "1.0.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "1.0.0",
"versionType": "semver"
}
],
"packageURL": "pkg:maven/org.apache.plc4x/plc4j-driver-opcua",
"packageName": "org.apache.plc4x:plc4j-driver-opcua",
"collectionURL": "https://repo.maven.apache.org/maven2",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-102508
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #4423 · Revision 1
- Added to Heist Feed
- Publisher date