UBUNTU-CVE-2026-55200

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Source

https://ubuntu.com/security/CVE-2026-55200

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55200.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-55200

Upstream

CVE-2026-55200

Downstream

USN-8486-1

Related

USN-8486-1

Published

2026-06-17T20:17:00Z

Modified

2026-07-01T23:43:25Z

Severity

8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
8.3 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L CVSS Calculator
9.2 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

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.

References

Affected packages

Ubuntu:25.10 / libssh2

Package

Name: libssh2
Purl: pkg:deb/ubuntu/libssh2?arch=source&distro=questing

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

1.11.1-1ubuntu0.25.10.2

Affected versions

1.*

1.11.1-1

1.11.1-1build1

1.11.1-1ubuntu0.25.10.1

Ecosystem specific

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.1-1ubuntu0.25.10.2"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55200.json"

Ubuntu:26.04:LTS / libssh2