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
ALPINE (1)
AZL (1)
BELL (1)
CGA (6)
DEBIAN (1)
ECHO (1)
JLSEC (1)
MGASA (1)
OESA (5)
openSUSE (2)
RHSA (1)
ROOT (2)
SUSE (9)
UBUNTU (1)
Related
openSUSE (2)
SUSE (9)
Published
2026-06-18T20:18:29Z
Modified
2026-09-14T18:27:01Z
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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                "251224371766184079981766064168826898112",
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                "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"