Is CVE-2026-55200 in the CISA KEV catalog?

No. CVE-2026-55200 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-55200?

CVE-2026-55200 has a CVSS v3 base score of 8.1 (HIGH).

What is the EPSS score for CVE-2026-55200?

CVE-2026-55200 has an EPSS score of 0.55% (41th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-55200

HIGH

8.1

CVSS v3

NVD

Description

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2_transport_read() that fails to enforce upper bounds on packet_length field. Remote attackers can send crafted SSH packets with excessively large packet_length values to corrupt heap memory and achieve remote code execution.

CWE-680

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

0.55%probability of exploitation in 30 days

41stpercentile

Moderate risk: more likely to be exploited than 41% 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 2026-06-22.