Missing authorization in Apache Pulsar entry filter endpoints
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-862.
Summary
Apache Pulsar from 3.3.0 before 4.0.14 and from 4.1.0 before 4.2.5 lacks an authorization check on admin endpoints for non-persistent topic entry filter policies (CWE-862). An authenticated user with produce or consume permission on the topic, but not permission to manage its policies, can read, replace or remove that policy. Exploitation requires installed entry filters and allowOverrideEntryFilters, which are not enabled by default.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
The Apache Pulsar broker admin REST API provides endpoints to read, set and remove the topic-level entry filter policy of a topic. For persistent topics these endpoints check that the caller is authorized for the entry filters topic policy operation. The corresponding endpoints for non-persistent topics (/admin/v2/non-persistent/{tenant}/{namespace}/{topic}/entryFilters) do not perform this authorization check. The only authorization check these endpoints perform is an indirect lookup permission check, made while the topic's partition metadata is retrieved; it is present in all affected versions. As a result, when authentication and authorization are enabled, an authenticated user who has been granted produce or consume permission on a non-persistent topic, or on its namespace, but not permission to manage the topic's policies can read, replace or remove the topic-level entry filter policy of that topic. These operations should be restricted to users with the tenant admin role or the superuser role. This impact analysis assumes that Pulsar has been configured with the default authorization provider. For custom authorization providers, the impact could be slightly different. The practical impact is limited by two broker configuration requirements, neither of which is met by default: - Entry filters must have been installed by the operator. Entry filter implementations are loaded only at broker startup from the broker's entry filters directory, which is empty by default. A request can only select among entry filters the operator has already deployed; setting any other filter name is rejected. The issue does not allow a caller to install or load entry filter code or to run arbitrary code in the broker. - Topic-level entry filter policies must be allowed to override the broker-level configuration (allowOverrideEntryFilters, which is disabled by default). When this setting is disabled, the topic-level entry filter policy has no effect on message dispatch. In deployments where both conditions are met, an unauthorized user can remove the topic-level entry filter policy of a non-persistent topic, for example one used to restrict which messages are delivered to consumers, or apply a different installed entry filter that withholds messages from subscriptions of that topic. Removing it makes the topic fall back to the namespace-level or broker-level entry filters, which are not removed. A changed policy affects only subscription dispatchers created after the change, for example for new subscriptions or when a subscription is re-created after all of its consumers have disconnected; dispatchers that already exist keep the entry filters they were created with. Because non-persistent topics do not store messages, messages withheld by an entry filter are not delivered. Reading the policy discloses only the names of the configured entry filters. The issue does not allow reading message contents, and entry filters cannot modify message payloads. Persistent topics and namespace-level entry filter policies are not affected. Apache Pulsar versions before 3.3.0 are not affected, because in those versions the entry filters topic policy check is made in code shared by the persistent and non-persistent endpoints. This issue affects Apache Pulsar versions from 3.3.0 before 4.0.14 and from 4.1.0 before 4.2.5. - 3.3.x and 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. The currently supported Apache Pulsar release lines are 4.0.x and 5.0.x. The supported versions schedule is available at https://pulsar.apache.org/contribute/release-policy/. Users who cannot upgrade immediately and have deployed entry filters should keep allowOverrideEntryFilters at its default value of false, so that topic-level entry filter policies do not affect message dispatch.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Apache Pulsar to 4.0.14 if it is in the range from 3.3.0 before 4.0.14, or to 4.2.5 if it is in the range from 4.1.0 before 4.2.5.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Apache Pulsar (Apache Software Foundation) Fixed in 4.0.14, 4.2.5
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Apache Pulsar 4.0.14, 4.2.5
14 records Highest priority Priority MEDIUM 1 MEDIUM, 13 LOW
Other records, highest priority first
- TI-2026-78917 Apache Pulsar accepts unverified token roles on anonymous requestsPriority MEDIUM 41
- TI-2026-78944 Apache Pulsar shadow topics lack authorization on source topicsPriority LOW 39
- TI-2026-78948 Path traversal in Apache Pulsar exposes packages of other tenantsPriority LOW 36
Timeline
- 2026-10-21 Threatist record created from CVE-2026-105932
- 2026-10-21 Alias added: GHSA-6xq3-9hvx-9qxg
- 2026-10-24 CISA SSVC decision points changed
References
More Apache vulnerabilities
- TI-2025-18529 Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT KEVCVSS 3.1CRITICAL 10.0
- TI-2024-30292 Apache OFBiz: Confused controller-view authorization logic (forced browsing) KEVCVSS 3.1CRITICAL 9.8
- TI-2024-26062 Apache OFBiz: Unauthenticated endpoint could allow execution of screen rendering code KEVCVSS 3.1CRITICAL 9.8
- TI-2024-21190 Apache OFBiz: Path traversal leading to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2024-18186 Apache HugeGraph-Server: Command execution in gremlin KEVCVSS 3.1CRITICAL 9.8
- TI-2023-25106 Deserialization of untrusted data in Apache ActiveMQ KEVCVSS 3.1CRITICAL 10.0
Sources
- CVE-2026-105932 · CVE Program
- CVE-2026-105932 · NVD
- FIRST EPSS
- GHSA-6xq3-9hvx-9qxg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences