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HighVulnerabilityCVE-2026-114230updated 29 Oct 2026, 14:47 UTC

Apache Qpid Proton C can be tricked into skipping login checks

A messaging library could let an unauthenticated sender slip past the login step. Whether this matters depends on how each application handles connections that have not finished logging in.

Official, 3 sources
SeverityHighVulnerability
Being exploited?UnclearNo reports either way yet
Fix available?UnclearNo fixed version published in the sources yet
How sure is this?Official, 3 sourcesBacked by an official source

How the attack works simplified

  1. 1Attacker connectsSends AMQP-formatted frames to the service
  2. 2Frame labeled SASLFrame claims to be part of authentication
  3. 3Library dispatches itProton treats it as an AMQP frame
  4. 4Login step skippedNo user name is set
  5. ResultUnauthenticated access may be possible

What happened

Apache Qpid Proton C dispatches regular AMQP frames when they claim to be SASL frames during peer authentication, allowing an authentication bypass in versions through 0.40.0.

Why it is dangerous: An attacker who can connect to an affected service may send messages before authentication completes, with no user name set, so impact depends on the application's handling of unauthenticated peers.

Are you affected?

You are affected if you run Apache Qpid Proton C 0.40.0 or earlier in a service that accepts AMQP connections from untrusted peers.

Apache Qpid Proton C through 0.40.0

What to do

  1. Check whether your application uses Apache Qpid Proton C version 0.40.0 or earlier
  2. Restrict AMQP access to trusted networks until a fixed version is confirmed
  3. Watch the Apache Qpid Proton project for an upgrade release and apply it

Timeline

  1. 28 Oct 2026, 20:46 UTC
    Publicly disclosed
  2. 28 Oct 2026, 20:46 UTC
    Reported by oss-security · oss-security
  3. 28 Oct 2026, 21:00 UTC
    Picked up by Zero Radar
  4. 29 Oct 2026, 11:22 UTC
    NVD reported on it · NVD
  5. 29 Oct 2026, 14:47 UTC
    GitHub Advisory reported on it · GitHub Advisory

Sources 3 reports, oldest first

Official vendor, government CERT or advisory database

Security researchers research teams and mailing lists

Technical details

ID
CVE-2026-114230 · GHSA-v3qr-mjxm-7376
EPSS
0.3% chance of exploitation within 30 days
Disclosed
28 Oct 2026, 20:46 UTC
On Zero Radar
28 Oct 2026, 21:00 UTC (15 min after disclosure)
Last change
29 Oct 2026, 14:47 UTC

The plain-language parts and the attack diagram were written by an AI model (anthropic/claude-haiku-5.5) from the sources above. Facts like versions, exploitation and dates come from the sources themselves. How Zero Radar works

Apache Qpid Proton C can be tricked into skipping login checks · Zero Radar