CVE-2026-55200

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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
ALPINE (1)
AZL (1)
BELL (1)
CGA (6)
DEBIAN (1)
ECHO (1)
JLSEC (1)
MGASA (1)
MINI (1)
openSUSE (2)
RHSA (1)
ROOT (2)
SUSE (2)
UBUNTU (1)
Related
openSUSE (2)
SUSE (2)
Published
2026-06-17T19:03:15Z
Modified
2026-09-19T08:08:55Z
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 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.

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

Affected packages

Git / github.com/libssh2/libssh2

Affected ranges

Type
GIT
Repo
https://github.com/libssh2/libssh2
Events
Introduced
a312b43325e3383c865a87bb1d26cb52e3292641
Fixed
97acf3dfda80c91c3a8c9f2372546301d4a1a7a8
Database specific
Show details 
{
    "cpe":  "cpe:2.3:a:libssh2:libssh2:1.11.1:*:*:*:*:*:*:*",
    "extracted_events":  [
        {
            "introduced":  "1.11.1"
        },
        {
            "last_affected":  "1.11.1"
        }
    ],
    "source":  [
        "CPE_STRING",
        "REFERENCES"
    ]
}

Affected versions

1.*
1.11.1
libssh2-1.*
libssh2-1.11.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55200.json"
vanir_signatures 
[
    {
        "deprecated":  false,
        "digest":  {
            "line_hashes":  [
                "141284426602951877244048188813499579259",
                "143473284225173970337868642692660082915",
                "239476351730145920916386564352533292186",
                "186841941824073284665751444935760647525",
                "231959736810542483406341454873690778984"
            ],
            "threshold":  0.9
        },
        "id":  "CVE-2026-55200-959b9c2e",
        "signature_type":  "Line",
        "signature_version":  "v1",
        "source":  "https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8",
        "target":  {
            "file":  "src/transport.c"
        }
    },
    {
        "deprecated":  false,
        "digest":  {
            "function_hash":  "199057862071948971514444742776006168965",
            "length":  7507
        },
        "id":  "CVE-2026-55200-a735b935",
        "signature_type":  "Function",
        "signature_version":  "v1",
        "source":  "https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8",
        "target":  {
            "file":  "src/transport.c",
            "function":  "ssh2_transport_read"
        }
    }
]
vanir_signatures_modified 
"2026-09-19T08:08:55Z"