9.3

CVE-2026-96770: temporal technologies, inc. s2s-proxy

CVSS: 9.3v4.0CriticalDeferred
Published 23-09-2026Last modified 23-09-2026
Open JSON

Vulnerability summary

CVE-2026-96770 is a critical (CVSS 9.3) vulnerability in temporal technologies, inc. s2s-proxy. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.9% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.3/10
010
Critical · v4.0 (CVE.org)
EPSS score
0.25%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 23-09-2026
    PublishedVulnerability first disclosed.
  2. 23-09-2026
    Last modifiedVulnerability information updated.

Description

All published s2s-proxy versions through 0.2.2 are affected. In versions 0.1.16 through 0.2.2, TLS server listeners use Go's RequireAnyClientCert mode when skipCAVerification is false. This mode checks that the client holds the certificate's private key but does not verify the certificate against the configured CA. An attacker can therefore use a self-signed certificate and key to establish a TLS and yamux connection, then invoke RPCs allowed by the proxy's configuration and Temporal credentials. No certificate or private key trusted by the deployment, and no Temporal credential, is required.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

16%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

24-09-202619-10-2026
EPSS score
0.25%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Temporal technologies, inc.1 product

1 vendor · 1 product

References

5 links