Is CVE-2025-5399 in the CISA KEV catalog?

No. CVE-2025-5399 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2025-5399?

CVE-2025-5399 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2025-5399?

CVE-2025-5399 has an EPSS score of 1.23% (65th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2025-5399

HIGH

7.5

CVSS v3

NVD

Description

Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the application to escape or exit this loop other than killing the thread/process. This might be used to DoS libcurl-using application.

CWE-835

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

1.23%probability of exploitation in 30 days

65thpercentile

Moderate risk: more likely to be exploited than 65% 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 2025-07-30.