CVE-2025-15661

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Source
https://cve.org/CVERecord?id=CVE-2025-15661
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-15661.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-15661
Downstream
Related
Published
2026-06-18T20:18:29Z
Modified
2026-08-27T18:26:11Z
Severity
  • 8.3 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c
Details

libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.

Database specific 
{
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
        "CWE-125"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/15xxx/CVE-2025-15661.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
2dae3024897e1898d389835151f4e9606227721d
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-2025-15661.json"
vanir_signatures 
[
    {
        "deprecated": false,
        "digest": {
            "function_hash": "168210165665412396151731718401882721581",
            "length": 4032
        },
        "id": "CVE-2025-15661-82a0aa80",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libssh2/libssh2/commit/2dae3024897e1898d389835151f4e9606227721d",
        "target": {
            "file": "src/sftp.c",
            "function": "sftp_symlink"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
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                "260269745362339246295813673629579944710",
                "213201341029398392648541015418666980500",
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                "138897454102779695311071437156442182934",
                "104481968113985420078698606058995563551",
                "108237734567789252916407989877833018662",
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                "39681718987685451413302644161348987020",
                "306591882004412172043897812544507701196",
                "184586940714455164170626214793055235645",
                "225535752505550988208604662343482693205",
                "186304888727167792546543748773403985673",
                "267583222670584456445189804748637348059",
                "312368730884693564382226980481615049741",
                "41889211057231649460008223450122831976",
                "51531198988979421224952243532283853268",
                "26218469403627074921444089484671283641",
                "101788498319277498070741377090110462617",
                "114885644006148405884751726793148785169",
                "61278427107303769730745179092561770182",
                "43857854357345764387203706083705176487"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2025-15661-8f81066e",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libssh2/libssh2/commit/2dae3024897e1898d389835151f4e9606227721d",
        "target": {
            "file": "src/sftp.c"
        }
    }
]
vanir_signatures_modified 
"2026-08-12T15:13:19Z"