Resource exhaustion in Temporal Oss Server

CVE-2025-8396

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.

Published · last modified .

EPSS exploit prediction

EPSS: 0.004 (30.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-8396: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-8396?
CVE-2025-8396 is a vulnerability in Temporal Oss Server, classified under Allocation of Resources Without Limits or Throttling. Published 2025-09-15.
Is CVE-2025-8396 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.