CVE-2025-8396: Medium severity Temporal OSS Server vulnerability

Published Sep 15, 2025
·
Updated

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.

Other sources

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.

MITRE

Affected Software

5 affected componentsFixes available
Temporal OSS Server<1.26.3, <1.27.3, <1.28.1
go/go.temporal.io/server>=1.28.0-129.0<1.28.1
1.28.1
go/go.temporal.io/server>=1.27.0-126.0<1.27.3
1.27.3
go/go.temporal.io/server<1.26.3
1.26.3
IBM Concert Software<=1.0.0-2.2.0

Remediation

Information

Upgrade to a fixed release: v1.26.3, v1.27.3, v1.28.1 or later (latest recommended).

Event History

Sep 15, 2025
CVE Published
via MITRE·02:13 PM
Data Sourced
via MITRE·02:13 PM
RemedyDescriptionWeakness
Data Sourced
via NVD·03:15 PM
DescriptionSeverityWeakness
Advisory Published
via GitHub·03:31 PM
Data Sourced
via GitHub·03:31 PM
DescriptionWeaknessAffected Software
Mar 23, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2025-8396?

CVE-2025-8396 is classified as a denial of service vulnerability due to insufficient bounds checking on the authorization header.

2

How do I fix CVE-2025-8396?

To fix CVE-2025-8396, upgrade to Temporal OSS Server versions 1.26.3, 1.27.3, or 1.28.1.

3

What platforms are affected by CVE-2025-8396?

CVE-2025-8396 affects all platforms running Temporal OSS Server prior to versions 1.26.3, 1.27.3, and 1.28.1.

4

What could happen if CVE-2025-8396 is exploited?

Exploitation of CVE-2025-8396 could lead to excessive memory allocation, potentially causing denial of service for the Temporal server.

5

Is there a specific version of Temporal OSS Server that addresses CVE-2025-8396?

Yes, CVE-2025-8396 is addressed in Temporal OSS Server versions 1.26.3, 1.27.3, and 1.28.1.

Contact

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