CVE-2026-55200

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-55200
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55200.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-55200
Downstream
Related
Published
2026-06-17T19:03:15.183Z
Modified
2026-07-08T08:12:42.024802914Z
Severity
  • 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
Summary
libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c
Details

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread() that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve remote code execution.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55200.json",
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
        "CWE-680"
    ]
}
References

Affected packages

Git / github.com/libssh2/libssh2

Affected ranges

Type
GIT
Repo
https://github.com/libssh2/libssh2
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
97acf3dfda80c91c3a8c9f2372546301d4a1a7a8
Database specific 
{
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ],
    "cpe": "cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "1.11.1"
        }
    ]
}

Affected versions

RELEASE.*
RELEASE.0.1
RELEASE.0.10
RELEASE.0.11
RELEASE.0.12
RELEASE.0.13
RELEASE.0.14
RELEASE.0.15
RELEASE.0.16
RELEASE.0.17
RELEASE.0.18
RELEASE.0.3
RELEASE.0.5
RELEASE.0.6
RELEASE.0.7
RELEASE.0.8
RELEASE.1.0
RELEASE.1.1
beforenb-0.*
beforenb-0.14
beforenb2-0.*
beforenb2-0.14
libssh2-1.*
libssh2-1.10.0
libssh2-1.11.0
libssh2-1.11.1
libssh2-1.2
libssh2-1.2.1
libssh2-1.2.3
libssh2-1.2.4
libssh2-1.2.5
libssh2-1.2.6
libssh2-1.2.7
libssh2-1.2.8
libssh2-1.2.9
libssh2-1.3.0
libssh2-1.4.0
libssh2-1.4.1
libssh2-1.4.2
libssh2-1.4.3
libssh2-1.5.0
libssh2-1.6.0
libssh2-1.7.0
libssh2-1.8.0
libssh2-1.9.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55200.json"