Is CVE-2015-4000 in the CISA KEV catalog?

No. CVE-2015-4000 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2015-4000?

CVE-2015-4000 has a CVSS v3 base score of 3.7 (LOW).

What is the EPSS score for CVE-2015-4000?

CVE-2015-4000 has an EPSS score of 99.86% (100th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2015-4000

LOWEPSS 100th pctl

3.7

CVSS v3

NVD

Description

The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the "Logjam" issue.

CWE-310 CWE-295Improper Certificate Validation

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Exploit Intelligence

99.86%probability of exploitation in 30 days

100thpercentile

Very high risk: more likely to be exploited than 100% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-27.