temporal up to 1.29.4/1.30.2 authorization

Summaryinfo

A vulnerability described as problematic has been identified in temporal up to 1.29.4/1.30.2. Impacted is an unknown function. The manipulation results in authorization. This vulnerability is cataloged as CVE-2026-5199. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic has been found in temporal up to 1.29.4/1.30.2. Affected is an unknown code block. The manipulation with an unknown input leads to a authorization vulnerability. CWE is classifying the issue as CWE-639. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. This is going to have an impact on integrity, and availability. CVE summarizes:

A writer role user in an attacker-controlled namespace could signal, delete, and reset workflows or activities in a victim namespace on the same cluster. Exploitation requires the attacker to know or guess specific victim workflow ID(s) and, for signal operations, signal names. This was due to a bug introduced in Temporal Server v1.29.0 which inadvertently allowed an attacker to control the namespace name value instead of using the server's own trusted name value within the batch activity code. The batch activity validated the namespace ID but did not cross-check the namespace name against the worker's bound namespace, allowing the per-namespace worker's privileged credentials to operate on an arbitrary namespace. Exploitation requires a server configuration where internal components have cross-namespace authorization, such as deployment of the internal-frontend service or equivalent TLS-based authorization for internal identities. This vulnerability also impacted Temporal Cloud when the attacker and victim namespaces were on the same cell, with the same preconditions as self-hosted clusters.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-5199 since 03/31/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. There are neither technical details nor an exploit publicly available.

Upgrading to version 1.29.5 or 1.30.3 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-17995). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

• temporal

Version

• 1.29.0
• 1.29.1
• 1.29.2
• 1.29.3
• 1.29.4
• 1.30.0
• 1.30.1
• 1.30.2

CPE 2.3info

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CPE 2.2info

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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