CVE-2025-26466

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/26xxx/CVE-2025-26466.json",
    "cna_assigner": "redhat",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "9.5p1"
                },
                {
                    "last_affected": "9.9p1"
                }
            ]
        }
    ],
    "cwe_ids": [
        "CWE-770"
    ]
}

References

Affected packages

Git / github.com/openssh/openssh-portable

Affected ranges

Type

GIT

Repo

https://github.com/openssh/openssh-portable

Events

Introduced

80a2f64b8c1d27383cc83d182b73920d1e6a91f1

Last affected

53a80baaebda180f46e6e8571f3ff800e1f5c496

Database specific

{
    "cpe": [
        "cpe:2.3:a:openbsd:openssh:9.5:p1:*:*:*:*:*:*",
        "cpe:2.3:a:openbsd:openssh:9.6:-:*:*:*:*:*:*",
        "cpe:2.3:a:openbsd:openssh:9.6:p1:*:*:*:*:*:*",
        "cpe:2.3:a:openbsd:openssh:9.7:-:*:*:*:*:*:*",
        "cpe:2.3:a:openbsd:openssh:9.7:p1:*:*:*:*:*:*",
        "cpe:2.3:a:openbsd:openssh:9.8:-:*:*:*:*:*:*",
        "cpe:2.3:a:openbsd:openssh:9.8:p1:*:*:*:*:*:*",
        "cpe:2.3:a:openbsd:openssh:9.9:p1:*:*:*:*:*:*"
    ],
    "extracted_events": [
        {
            "introduced": "9.5-p1"
        },
        {
            "last_affected": "9.5-p1"
        },
        {
            "introduced": "9.6-NA"
        },
        {
            "last_affected": "9.6-NA"
        },
        {
            "introduced": "9.6-p1"
        },
        {
            "last_affected": "9.6-p1"
        },
        {
            "introduced": "9.7-NA"
        },
        {
            "last_affected": "9.7-NA"
        },
        {
            "introduced": "9.7-p1"
        },
        {
            "last_affected": "9.7-p1"
        },
        {
            "introduced": "9.8-NA"
        },
        {
            "last_affected": "9.8-NA"
        },
        {
            "introduced": "9.8-p1"
        },
        {
            "last_affected": "9.8-p1"
        },
        {
            "introduced": "9.9-p1"
        },
        {
            "last_affected": "9.9-p1"
        }
    ],
    "source": "CPE_STRING"
}

Affected versions

9.*

9.5-p1

9.6-NA

9.7-NA

9.8-NA

9.9-p1

Other

V_9_5_P1

V_9_6_P1

V_9_7_P1

V_9_9_P1

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-26466.json"