CVE-2026-82180 Auth bypass in Eclipse Arrowhead
Attackers can bypass MQTT authentication by sending unverified self-signed certificates, gaining system operator privileges and full management access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-82180?
CVE-2026-82180 is a critical authentication bypass vulnerability in Eclipse Arrowhead, published on 3 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Which versions are affected by CVE-2026-82180?
How do I fix CVE-2026-82180?
No fix has been published for CVE-2026-82180 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-82180 being exploited?
There is no known exploitation of CVE-2026-82180 in the wild and no public exploit code.
Sources
Also known as GHSA-268c-4cfr-fmcj.