CVE-2026-96770

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.31% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 24.6% of scored records. A rank, not a probability.

NVD base score

9.3 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-09-24.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-09-23 18:58Z1 MO AGO

Last updated

2026-09-23 19:36Z1 MO AGO

Reserved

2026-09-23

Assigning CNA

Temporal

Record state

PUBLISHED

Severity

Critical (CVSS 9.3)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:H

Weaknesses

• CWE-296Improper Following of a Certificate's Chain of TrustBase

Data version

5.2

Document digest

8c7a2b0f67fb42a6cb0cd7b6c58c5a9a195e178261fcd6e0852d925ec43a1f76

• github.comAffected TLS server configuration in s2s-proxy 0.2.2https://github.com/temporalio/s2s-proxy/blob/v0.2.2/encryption/tls.go#L47-L62product
• github.comChange that introduced the affected certificate verification modehttps://github.com/temporalio/s2s-proxy/commit/d100c2258dbc37d7df51298ea045315f36c7eb3bproduct
• github.comFix pull requesthttps://github.com/temporalio/s2s-proxy/pull/296patch
• github.comFix commithttps://github.com/temporalio/s2s-proxy/commit/f1dc6b9a3919d37e82545ab461cbe6bb62618d3cpatch
• docs.temporal.ioTemporal Payload Codec and Codec Server documentationhttps://docs.temporal.io/production-deployment/data-encryption#codec-server-setupproduct