Is CVE-2025-56233 in the CISA KEV catalog?

No. CVE-2025-56233 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2025-56233?

CVE-2025-56233 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2025-56233?

CVE-2025-56233 has an EPSS score of 0.30% (22th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2025-56233

HIGH

7.5

CVSS v3

NVD

Description

Openindiana, kernel SunOS 5.11 has a denial of service vulnerability. For the processing of TCP packets with RST or SYN flag set, Openindiana has a wide acceptable range of sequence numbers. It does not require the sequence number to exactly match the next expected sequence value, just to be within the current receive window, which violates RFC5961. This flaw allows attackers to send multiple random TCP RST/SYN packets to hit the acceptable range of sequence numbers, thereby interrupting normal connections and causing a denial of service attack.

CWE-400Resource Exhaustion

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

0.30%probability of exploitation in 30 days

22ndpercentile

Low risk: more likely to be exploited than 22% of all known CVEs.

References

https://github.com/zq-star/TCP-Vuln-Report/blob/master/Openindiana%20minimal/tcp-rst-syn/openindiana-minimal-tcp-rst-syn.md

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

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 2025-10-28.