CVE-2025-8396: Go.temporal.io/server Remote Code Execution Vulnerability

MODERATE
Advisory Identifier: GHSA-p768-c3pr-6459
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CWE-770
Published
Advisory Summary

CVE-2025-8396 is a MODERATE remote code execution vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Go.temporal.io/server libraries in the Go ecosystem. The issue involves temporal oss server vulnerable to allocation of resources without limits or throttling. Remediation is available by upgrading affected packages to version 1.26.3, 1.27.3, 1.28.1.

CVE-2025-8396 at a Glance

CVE Identifier CVE-2025-8396
GHSA Identifier GHSA-p768-c3pr-6459
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Go.temporal.io/server
Package Ecosystem Go
Published Date
Last Updated

How to Fix CVE-2025-8396

To remediate this vulnerability, upgrade all affected Go.temporal.io/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.

go.temporal.io/server fixed: 1.26.3 
Upgrade go.temporal.io/server to 1.26.3
go.temporal.io/server fixed: 1.27.3 
Upgrade go.temporal.io/server to 1.27.3
go.temporal.io/server fixed: 1.28.1 
Upgrade go.temporal.io/server to 1.28.1
Verify Direct and Transitive Dependencies

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-2025-8396, inspect your project dependencies for Go.temporal.io/server:

inspect dependencies for go.temporal.io/server

Analyze the terminal output to locate any version of Go.temporal.io/server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.26.3), 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-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Go.temporal.io/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

Insufficiently specific bounds checking on authorization header could lead to denial of service in the Temporal server on all platforms due to excessive memory allocation. This issue affects all platforms and versions of OSS Server prior to 1.26.3, 1.27.3, and 1.28.1 (i.e., fixed in 1.26.3, 1.27.3, and 1.28.1 and later). Temporal Cloud services are not impacted.

CVE-2025-8396 Affected Go.temporal.io/server Versions

3 component(s)
Fixed Versions:
1.26.31.27.31.28.1
Product / Package Ecosystem Affected Versions Fixed Version
go.temporal.io/server
golang/go.temporal.io/server
Go
< 1.26.3
1.26.3
go.temporal.io/server
golang/go.temporal.io/server
Go
≥ 1.27.0-126.0
< 1.27.3
1.27.3
go.temporal.io/server
golang/go.temporal.io/server
Go
≥ 1.28.0-129.0
< 1.28.1
1.28.1

References

NVD — CVE-2025-8396 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-8396
Go.temporal.io/server Source Repository REPOSITORY
https://github.com/temporalio/temporal
Go.temporal.io/server Release RELEASE
https://github.com/temporalio/temporal/releases/tag/v1.26.3
Go.temporal.io/server Release RELEASE
https://github.com/temporalio/temporal/releases/tag/v1.27.3
Go.temporal.io/server Release RELEASE
https://github.com/temporalio/temporal/releases/tag/v1.28.1

Frequently Asked Questions

What is CVE-2025-8396?
CVE-2025-8396 is a security vulnerability in Go.temporal.io/server involving Temporal OSS Server Vulnerable to Allocation of Resources Without Limits or Throttling under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Go.temporal.io/server versions are affected?
Affected versions include releases prior to 1.26.3, 1.27.3, 1.28.1 across affected packages: go.temporal.io/server.
What version fixes CVE-2025-8396?
Upgrading to 1.26.3, 1.27.3, 1.28.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is go.temporal.io/server affected?
Yes, go.temporal.io/server is affected in releases prior to 1.26.3, 1.27.3, 1.28.1. Upgrade your dependency to 1.26.3, 1.27.3, 1.28.1 or later.
What CWE is associated with CVE-2025-8396?
CVE-2025-8396 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check Go dependencies for CVE-2025-8396?
Run the dependency tree command: 'inspect dependencies for go.temporal.io/server'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-p768-c3pr-6459",
  "modified" : "2025-09-15T21:51:27Z",
  "published" : "2025-09-15T15:31:31Z",
  "aliases" : [ "CVE-2025-8396" ],
  "summary" : "Temporal OSS Server Vulnerable to Allocation of Resources Without Limits or Throttling",
  "details" : "Insufficiently specific bounds checking on authorization header could lead to denial of service in the Temporal server on all platforms due to excessive memory allocation. This issue affects all platforms and versions of OSS Server prior to 1.26.3, 1.27.3, and 1.28.1 (i.e., fixed in 1.26.3, 1.27.3, and 1.28.1 and later). Temporal Cloud services are not impacted.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "go.temporal.io/server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.26.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "go.temporal.io/server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.27.0-126.0"
      }, {
        "fixed" : "1.27.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "go.temporal.io/server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.28.0-129.0"
      }, {
        "fixed" : "1.28.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-8396"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/temporalio/temporal"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/temporalio/temporal/releases/tag/v1.26.3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/temporalio/temporal/releases/tag/v1.27.3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/temporalio/temporal/releases/tag/v1.28.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-09-15T21:51:27Z",
    "nvd_published_at" : "2025-09-15T15:15:55Z"
  }
}