temporal-proxy 0.2.0 through 0.8.0 does not bind encrypted payloads to the namespace they were encrypted for. When payload encryption is enabled, the proxy chooses the decryption key by an identifier stored in the payload rather than by the namespace of the request, and nothing in the ciphertext records that namespace. A caller whom the proxy authorizes only for namespace B, and who has obtained an encrypted payload from namespace A, can therefore have the proxy decrypt it. In 0.8.0, the caller can submit the payload to the codec server's /decode endpoint. In every affected version, a caller who can also write to namespace B on the Temporal server directly can place the payload there and read it back through the proxy. This holds whether namespaces share the default key or each has its own, because a single proxy holds every key it is configured with. The issue does not give the attacker encrypted payloads they could not already obtain, and does not allow encrypted payloads to be modified.
History

Tue, 27 Oct 2026 04:30:00 +0000

Type Values Removed Values Added
First Time appeared Temporal
Temporal temporal-proxy
Vendors & Products Temporal
Temporal temporal-proxy

Fri, 16 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 15 Oct 2026 19:15:00 +0000

Type Values Removed Values Added
Description temporal-proxy 0.2.0 through 0.8.0 does not bind encrypted payloads to the namespace they were encrypted for. When payload encryption is enabled, the proxy chooses the decryption key by an identifier stored in the payload rather than by the namespace of the request, and nothing in the ciphertext records that namespace. A caller whom the proxy authorizes only for namespace B, and who has obtained an encrypted payload from namespace A, can therefore have the proxy decrypt it. In 0.8.0, the caller can submit the payload to the codec server's /decode endpoint. In every affected version, a caller who can also write to namespace B on the Temporal server directly can place the payload there and read it back through the proxy. This holds whether namespaces share the default key or each has its own, because a single proxy holds every key it is configured with. The issue does not give the attacker encrypted payloads they could not already obtain, and does not allow encrypted payloads to be modified.
Title temporal-proxy payload decryption is not bound to the request namespace
Weaknesses CWE-639
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Temporal

Published: 2026-10-15T19:09:30.743Z

Updated: 2026-10-16T15:20:20.801Z

Reserved: 2026-10-09T14:47:54.417Z

Link: CVE-2026-108126

cve-icon Vulnrichment

Updated: 2026-10-16T15:11:45.651Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-15T19:17:19.873

Modified: 2026-10-16T19:55:59.740

Link: CVE-2026-108126

cve-icon Redhat

No data.