CVE-2026-105945
Description
A flaw was found in Apache Pulsar. When the Packages Management Service is configured to use filesystem storage, it fails to validate package version identifiers against directory traversal sequences. An authenticated user with package permissions can exploit this flaw using parent directory references to access, overwrite, or delete packages belonging to other tenants or namespaces. This unauthorized manipulation can compromise the integrity and availability of dependent applications and services.
Statement
This vulnerability is rated as having Important impact because authenticated clients granted package management privileges can traverse directory boundaries to inspect, tamper with, or delete artifacts belonging to other tenants, potentially compromising dependent workloads such as Pulsar Functions, Sources, or Sinks. However, package management is disabled by default in Pulsar broker configurations, and standard deployments utilizing the default Apache BookKeeper storage backend are unaffected. Exploitation is constrained to environments where package management is explicitly enabled and configured to store artifacts on the broker's local filesystem.
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
The attacker may be able to create or overwrite critical files that are used to execute code, such as programs or libraries.
Integrity
Technical Impact: Modify Files or Directories
The attacker may be able to overwrite or create critical files, such as programs, libraries, or important data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, appending a new account at the end of a password file may allow an attacker to bypass authentication.
Confidentiality
Technical Impact: Read Files or Directories
The attacker may be able to read the contents of unexpected files and expose sensitive data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, by reading a password file, the attacker could conduct brute force password guessing attacks in order to break into an account on the system.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
The attacker may be able to overwrite, delete, or corrupt unexpected critical files such as programs, libraries, or important data. This may prevent the product from working at all and in the case of protection mechanisms such as authentication, it has the potential to lock out product users.
Frequently Asked Questions
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