CVE-2026-55200
Full vulnerability record from the local CVENow database.
Description
libssh2 1.11.1, fixed in commit 97acf3d, 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.
Severity
CRITICAL
CVSS score
9.2
(v4.0)
Vulnerability status
Modified
Source identifier
Published
2026-06-17 20:17:28.667000
Last modified
2026-10-22 19:17:55.937000
View original CVE JSON
{
"id": "CVE-2026-55200",
"sourceIdentifier": "[email protected]",
"published": "2026-06-17T20:17:28.667",
"lastModified": "2026-10-22T19:17:55.937",
"vulnStatus": "Modified",
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"value": "libssh2 1.11.1, fixed in commit 97acf3d, 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."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
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"product": "libssh2",
"defaultStatus": "unaffected",
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"packageURL": "pkg:github/libssh2/libssh2",
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"metrics": {
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"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
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{
"url": "https://www.vulncheck.com/advisories/libssh2-out-of-bounds-write-via-unchecked-packet-length-in-transport-c",
"source": "[email protected]",
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