CVE-2026-105933: Apache Pulsar: Namespace encryption requirement not enforced after a failure during topic initialization

DescriptionCVE.org

Apache Pulsar allows an administrator to require end-to-end message encryption for all topics in a namespace by setting the encryption_required namespace policy. When this policy is set, the broker rejects messages that are published without encryption. When the broker loads a persistent topic, it reads the namespace policies and the topic-level policies as part of topic initialization. If a step of this initialization fails, for example because of an error reading from the metadata store, a failure loading the topic-level policies or a failure in a later initialization step, the broker logs a warning, disables the encryption requirement for that topic, and completes the topic load as if it had succeeded. The topic is then served with encryption_required not enforced, even though the namespace policy requires it. Topic-level policies that could not be loaded are also not applied. While the encryption requirement is not enforced, an authenticated client with permission to produce to the affected topic can publish messages that are not encrypted, and the broker accepts and stores them. This applies both to producers created after the topic was loaded and to producers that were already connected. Messages published with encryption remain encrypted; the issue does not expose the content of encrypted messages or the encryption keys. The condition is not limited to transient failures. If the cause of the initialization failure persists, the encryption requirement is disabled again each time the topic is loaded, for example after a topic unload, a namespace bundle reassignment or a broker restart. An update to the namespace policies restores enforcement on a loaded topic, but only until the topic is loaded again. Enforcement is reliably restored only once the underlying cause of the failure has been resolved and the topic has been loaded again.

• Apache Software Foundation · Apache Pulsarfrom 1.22.0-incubating before 4.0.14; from 4.1.0 before 4.2.5

Exploitation

Unlikely (under 1%). EPSS under 1%, or no score yet.

CISA KEV

Not listed

Public check

No public nuclei template

Weakness

Not Failing Securely · Misconfiguration and Insecure Design

Vendor

Apache Software Foundation

Published

October 2026

Band

Unlikely (under 1%), October 2026

• NVD entrynvd.nist.gov
• CVE recordcve.org
• Weakness CWE-636cwe.mitre.org
• Vendor advisorypulsar.apache.org
• Vendor advisorylists.apache.org