CVE-2025-8396

Published Sep 15, 2025 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Solution

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


Vendor Workaround

Use mTLS, or bring your own claim mapper.

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
EUVD EUVD EUVD-2025-29200 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.
Github GHSA Github GHSA GHSA-p768-c3pr-6459 Temporal OSS Server Vulnerable to Allocation of Resources Without Limits or Throttling
History
Type Values Removed Values Added
First Time appeared Temporal
Temporal temporal
Vendors & Products Temporal
Temporal temporal
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Weaknesses CWE-770
References
Metrics cvssV4_0

{'score': 6.9, 'vector': '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/S:N/AU:Y'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Temporal
Published
Updated
Sep 15, 2025, 2:52 PM
Reserved
Jul 30, 2025, 8:55 PM
Status
Deferred
Published
Sep 15, 2025, 3:15 PM
Modified
Jun 17, 2026, 10:06 AM