Vulnerability · Published Sep 3, 2026 · Assigned by eclipse
CVE-2026-82180
Critical 9.5
In plain English
A critical-severity improper certificate validation in Eclipse Arrowhead from Eclipse Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities).
Official description
In Eclipse Arrowhead versions from 5.0.0 to 5.2.1 when the MQTT API is enabled with the certificate authentication policy, CertificateMqttFilter parses an X.509 certificate that the client sends inside the MQTT message payload (the authentication field of MqttRequestTemplate) and treats its Subject DN as the authenticated identity. The certificate is decoded with CertificateFactory.generateCertificate() but its signature is never verified and its issuer chain is never validated against any trust store. Authorisation is reduced to two string comparisons on attacker-supplied data: the DN-qualifier must equal "sy" or "op", and the cloud-name part of the CN must match the server's. Both values are public (the cloud name is in the server's own TLS certificate). An attacker who can publish to the MQTT broker can therefore mint a self-signed certificate with CN=Sysop.<cloud>.<org>.arrowhead.eu, dnQualifier=op, send it as the authentication field, and be authenticated as the cloud's system operator with isSysOp == true. This passes the downstream ManagementServiceMqttFilter (request.isSysOp() → allowed) and gives full management access over MQTT. The HTTP CertificateFilter is not affected — it reads the certificate from jakarta.servlet.request.X509Certificate, which Tomcat populates only after a successful mTLS handshake against the configured trust store.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Eclipse Foundation | Eclipse Arrowhead | 5.0.0 – through 5.2.1 |
Weakness: CWE-295, CWE-290 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:H