Vulnerability details

CVE-2026-104355

Temporal Technologies Temporal Server

Temporal Server applies inbound namespace replication from a connected peer cluster to local namespaces

CVSS 4.0
7.0High

Official description

A connected peer cluster can modify a Temporal Server cluster's local namespaces, which are never replicated to that peer, because the receiving cluster applies inbound namespace replication updates to them. In a multi-cluster deployment, each cluster pulls replication tasks from the remote clusters an administrator has registered with connection enabled; the sending side excludes local namespaces, but the receiving side does not apply the same rule. When an inbound task names an existing namespace, the server checks at most that the namespace identifiers match, then overwrites its state, description, owner, retention, archival settings, and cluster list, and its active cluster when the task carries a higher failover version, without checking that the namespace is global. A party that controls a registered peer's replies, by operating or compromising it, can therefore change any local namespace whose name and identifier it can supply, without any credential on the receiving cluster: for example, marking it Deprecated, making the peer its active cluster, and shortening its retention, after which new Workflow starts in that namespace fail. Local namespaces include the built-in temporal-system namespace. Namespace metadata the History service refreshes from the peer while processing its history replication tasks passes through the same logic. A cluster with no remote cluster registered with connection enabled is not exposed.

CVSS scores

ScoreVersionSourceVector
7.0High 4.0 CVEProject cvelistV5 (CNA) (Temporal) CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

Affected products

VendorProductVersionsSource
Temporal Technologies, Inc. Temporal Server v < 1.0.0 CVEProject cvelistV5 (CNA)
Temporal Technologies, Inc. Temporal Server 1.0.0 ≤ v ≤ 1.29.7 CVEProject cvelistV5 (CNA)
Temporal Technologies, Inc. Temporal Server 1.30.0 ≤ v < 1.30.8 CVEProject cvelistV5 (CNA)
Temporal Technologies, Inc. Temporal Server 1.31.0 ≤ v < 1.31.4 CVEProject cvelistV5 (CNA)
Temporal Technologies, Inc. Temporal Server 1.32.0 ≤ v < 1.32.1 CVEProject cvelistV5 (CNA)

References and advisories

9
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Details

Published
2026-10-12
Last updated
2026-10-16
State
Published
Assigner (CNA)
Temporal

Exploit prediction (EPSS)

0.35%
Probability of exploitation in 30 days
29.8%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
No
Exploitation
None
Technical impact
Partial

Weaknesses (CWE)

  • CWE-863
    Incorrect Authorization