Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

CVE-2026-5199

Gravedad CVSS v4.0:
BAJA
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
01/04/2026
Última modificación:
01/04/2026

Descripción

*** Pendiente de traducción *** 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&amp;#39;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&amp;#39;s bound namespace, allowing the per-namespace worker&amp;#39;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.<br /> <br /> <br /> <br /> <br /> 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.