CVE-2026-105935: Apache Pulsar: The Pulsar Functions Worker provides a REST API endpoint for triggering a function, which publishes a caller-supplied value to one of the function's configured input topics
This Apache advisory covers CVE-2026-105935 in Apache Pulsar.
Key facts
- Vendor rating
- Medium, CVSS 4.9
- CISA KEV
- Not listed (catalogue checked )
- Affected
- 2.0.0-rc1-incubating before 4.0.14; 4.1.0 before 4.2.5
- Fixed in
- 4.0.14, 4.2.5, 2.4.0
- Source published
- Source revised
- Listed by VulniPulse
- Record changed
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
The Pulsar Functions Worker provides a REST API endpoint for triggering a function, which publishes a caller-supplied value to one of the function's configured input topics.
The Functions Worker performs this publish with its own broker client, which authenticates with the Worker's configured broker-client credentials rather than the credentials of the API caller.
When authorization is enabled, in Apache Pulsar 2.4.0 and later versions, the trigger endpoint checks only that the caller is authorized to perform function operations in the function's namespace. It does not check that the caller is authorized to produce to the input topic that the message is published to.
Versions before 2.4.0 do not perform a caller authorization check for the trigger endpoint at all. Function input topics are not restricted to the function's own tenant or namespace, and registering a function does not require produce permission on its input topics.
As a result, an authenticated user who is authorized to manage functions in a namespace, for example a role granted the functions permission on that namespace, can cause the Functions Worker to publish messages with caller-controlled content to a topic that the user is not authorized to produce to, including topics in other tenants.
These messages are published under the identity of the Functions Worker.
Text from the source record.
- 2.0.0-rc1-incubating before 4.0.14
- 4.1.0 before 4.2.5
Official advisory · high-confidence parse· fetched ·verify at source
How to fix CVE-2026-105935
Upgrade to a fixed release named by Apache:
- 4.0.14
- 4.2.5
- 2.4.0
Vendor guidance
- This issue affects Apache Pulsar versions from 2.0.0-rc1-incubating before 4.0.14 and from 4.1.0 before 4.2.5. - 4.0.x version users should upgrade to at least 4.0.14. - 4.1.x and 4.2.x version users should upgrade to at least 4.2.5.
- Users operating versions prior to those listed above should upgrade to the aforementioned patched versions or newer versions.
- Users of Apache Pulsar 2.4.0 and later versions with authorization enabled who cannot upgrade immediately can limit the permission to manage functions to trusted roles.
Workarounds
- Users of versions before 2.4.0 should restrict access to the Functions Worker REST API to trusted callers, because in these versions the trigger endpoint does not check the caller's permission to manage functions.
CVE-2026-105935 in other vendors' advisories
- Red Hat: CVE-2026-105935, medium severity, fixed in 4.0.14, 4.2.5
More Apache Software Foundation advisories
CVE-2026-105945Oct 21, 2026Apache Pulsar: The Pulsar Packages Management ServiceCVE-2026-105942Oct 21, 2026Apache Pulsar: When a configured proxy role sends a request to the broker on behalfCVE-2026-105938Oct 21, 2026Apache Pulsar namespaces can restrictCVE-2026-105937Oct 21, 2026Apache Pulsar shadow topics (PIP-180) are topicsCVE-2026-105936Oct 21, 2026Apache Pulsar: The Pulsar Functions worker REST API provides two endpointsCVE-2026-105934Oct 21, 2026The Apache Pulsar broker admin REST API provides a truncate operation for persistent
Apache Software Foundation advisories, October 2026All Apache Software Foundation advisories
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