Vulnerabilities in pkg:golang/go.temporal.io/server
PACKAGECVE-2026-5199 is a LOW attacker-controlled namespace could signal, delete, vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting Temporal Server libraries in the Go ecosystem. The issue involves attacker-controlled namespace could signal, delete, and reset workflows or activities in a victim namespace on the same cluster. Remediation is available by upgrading affected packages to version 1.30.3, 1.29.5.
pkg:golang/go.temporal.io/server
Vulnerability advisories affecting package pkg:golang/go.temporal.io/server. Select an advisory below to view technical details or fixes.
| Advisory ID | CVE / NVD | Severity | Summary |
|---|---|---|---|
| GHSA-xpg8-3hhp-p7w8 | CVE-2026-5199 | LOW | Temporal Server: attacker-controlled namespace could signal, delete, and reset workflows or activities in a victim namespace on the same cluster |
| GHSA-q98v-9f9w-f49q | CVE-2026-5724 | MODERATE | Temporal does not enforce authentication and authorization for the streaming AdminService/StreamWorkflowReplicationMessages endpoint |
| GHSA-hmhp-gh8m-c8xp | CVE-2025-14987 | MODERATE | Temporal has an Incorrect Authorization vulnerability |
| GHSA-p2gr-hm8g-q772 | CVE-2025-14986 | LOW | Temporal has a namespace policy bypass allowing requests to be authorized for incorrect contexts |
| GHSA-p768-c3pr-6459 | CVE-2025-8396 | MODERATE | Temporal OSS Server Vulnerable to Allocation of Resources Without Limits or Throttling |
| GHSA-gm2g-2xr9-pxxj | CVE-2023-3485 | LOW | Temporal Server vulnerable to Incorrect Authorization and Insecure Default Initialization of Resource |
CVE-2026-5199 at a Glance
How to Fix CVE-2026-5199
To remediate this vulnerability, upgrade all affected Temporal Server dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade go.temporal.io/server to 1.30.3
Upgrade go.temporal.io/server to 1.29.5
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for go.temporal.io/server
How to Check if You Are Affected
To determine whether your application is affected by CVE-2026-5199, inspect your project dependencies for Temporal Server:
inspect dependencies for go.temporal.io/server
Analyze the terminal output to locate any version of Temporal Server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.30.3), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where 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. In Temporal Server, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-5199 Affected Temporal Server Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
go.temporal.io/server
|
Go |
≥ 1.30.0-143.0
< 1.30.3
|
1.30.3
|
|
go.temporal.io/server
|
Go |
< 1.29.5
|
1.29.5
|
References
Frequently Asked Questions
What is CVE-2026-5199?
Which Temporal Server versions are affected?
What version fixes CVE-2026-5199?
Is go.temporal.io/server affected?
What CWE is associated with CVE-2026-5199?
How can I check Go dependencies for CVE-2026-5199?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-xpg8-3hhp-p7w8",
"modified" : "2026-07-21T14:59:09Z",
"published" : "2026-04-01T18:36:38Z",
"aliases" : [ "CVE-2026-5199" ],
"summary" : "Temporal Server: attacker-controlled namespace could signal, delete, and reset workflows or activities in a victim namespace on the same cluster",
"details" : "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.\n\nThis vulnerability also impacted Temporal Cloud when the attacker and victim namespaces were on the same cell, with the same preconditions as self-hosted clusters.",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "go.temporal.io/server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "1.30.0-143.0"
}, {
"fixed" : "1.30.3"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "go.temporal.io/server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "1.29.5"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-5199"
}, {
"type" : "ADVISORY",
"url" : "https://github.com/advisories/GHSA-xpg8-3hhp-p7w8"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/temporalio/temporal"
}, {
"type" : "WEB",
"url" : "https://github.com/temporalio/temporal/releases/tag/v1.29.5"
}, {
"type" : "WEB",
"url" : "https://github.com/temporalio/temporal/releases/tag/v1.30.3"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-639" ],
"severity" : "LOW",
"github_reviewed" : true,
"github_reviewed_at" : "2026-04-03T23:25:37Z",
"nvd_published_at" : "2026-04-01T18:16:31Z"
}
}