Is CVE-2026-105942 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-105942 being exploited in the wild.

How severe is CVE-2026-105942?

Informational severity, published 21 October 2026.

Which products and versions are affected?

Apache Pulsar 2.8.1 to 4.0.13, 4.1.0 to 4.2.4.

How is CVE-2026-105942 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-105942?

Check whether you run Apache Pulsar at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-105942: Apache Pulsar proxy authorization bypass in multi-role token provider

CVE-2026-105942 · Severity: info · Published 2026-10-21

Apache Pulsar is a distributed messaging system used to handle high-volume data streams and event processing across enterprise applications. Two authorization flaws allow users proxied through an admin-level proxy role to bypass permission checks and perform unauthorized administrative operations or access data beyond their own permissions. An attacker controlling traffic through a compromised or malicious proxy can escalate privileges and take control of Pulsar tenants.

Technologies: Apache Pulsar. Vendors: Apache.

Quick answers

Is CVE-2026-105942 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-105942 being exploited in the wild.
How severe is CVE-2026-105942?: Informational severity, published 21 October 2026.
Which products and versions are affected?: Apache Pulsar 2.8.1 to 4.0.13, 4.1.0 to 4.2.4.
Is there a fix for CVE-2026-105942?: Yes: fixed in 4.0.14, 4.2.5. Until then: Ensure no proxy role is configured as a tenant admin or superuser role. For deployments using multi-role token authorization, configure proxies to forward client credentials to the broker instead of authenticating with the proxy's own token. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-105942 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-105942?: Check whether you run Apache Pulsar at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 4.0.14, 4.2.5

Ensure no proxy role is configured as a tenant admin or superuser role. For deployments using multi-role token authorization, configure proxies to forward client credentials to the broker instead of authenticating with the proxy's own token.

Technical details

The broker's proxy authorization check has two flaws: (1) when the multi-role token authorization provider is used, the original principal is authorized with the proxy's token roles instead of its own, allowing privilege escalation if the proxy holds superuser or tenant admin roles; (2) the tenant admin authorization check for proxied REST API requests succeeds if the proxy role is a tenant admin, without verifying the original principal has such permissions. Both flaws allow bypassing intended per-user permission enforcement in multi-role deployments.

Affected products

Apache Pulsar 2.8.1 to 4.0.13, 4.1.0 to 4.2.4

Timeline

2026-10-21: disclosed

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.