CVE-2026-66032

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Source
https://cve.org/CVERecord?id=CVE-2026-66032
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66032.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-66032
Downstream
Related
Published
2026-07-24T16:32:39Z
Modified
2026-08-27T18:26:16Z
Severity
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
libssh2 Double-Free Heap Corruption via sftp_open()
Details

libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites.

Database specific 
{
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
        "CWE-415"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66032.json"
}
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
5e4776146552d898b9c0e1b313cd093fa8dc92d0
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "1.11.1"
        }
    ],
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

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-2026-66032.json"
vanir_signatures 
[
    {
        "deprecated": false,
        "digest": {
            "function_hash": "33264403999217637035238251445367858212",
            "length": 5058
        },
        "id": "CVE-2026-66032-83cc2e9f",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libssh2/libssh2/commit/5e4776146552d898b9c0e1b313cd093fa8dc92d0",
        "target": {
            "file": "src/sftp.c",
            "function": "sftp_open"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "324192115594221831694647950376857451632",
                "336061196034926044958593142467814960912",
                "41304970594478553678543807861292796172",
                "332648750590961424773944216179931312826"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-66032-a50a072b",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libssh2/libssh2/commit/5e4776146552d898b9c0e1b313cd093fa8dc92d0",
        "target": {
            "file": "src/sftp.c"
        }
    }
]
vanir_signatures_modified 
"2026-08-12T16:09:59Z"