OESA-2026-3322 (CVE-2026-59843)

Vulnerability from osv_openeuler – Published: 2026-08-13 13:57 – Updated: 2026-08-13 13:57 – Source website
VLAI
Summary
libssh security update
Details

The ssh library was designed to be used by programmers needing a working SSH implementation by the mean of a library. The complete control of the client is made by the programmer. With libssh, you can remotely execute programs, transfer files, use a secure and transparent tunnel for your remote programs. With its Secure FTP implementation, you can play with remote files easily, without third-party programs others than libcrypto (from openssl).

Security Fix(es):

A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service.(CVE-2026-59843)

A flaw was found in libssh. A remote authenticated client can issue SSH_FXP_READ requests with an arbitrarily large length, causing a libssh SFTP server to allocate excessive memory and potentially exhaust it through repeated requests.(CVE-2026-59844)

A flaw was found in libssh. When ProxyCommand is used, an unchecked fork() failure can be stored as process ID -1; during cleanup, signals may then be sent across the caller's accessible process tree, leading to local denial of service.(CVE-2026-59845)

A flaw was found in libssh. Incorrect AES-GCM finalization checks in builds using the OpenSSL backend can effectively remove integrity protection, allowing an in-path attacker to modify plaintext on the wire without detection.(CVE-2026-59847)

A flaw was found in libssh. If data packets are processed after a channel is closed, channel data callbacks can be invoked after the associated data has already been freed, leading to crashes or possible use-after-free conditions.(CVE-2026-59850)

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "libssh-0.9.6-21.oe2203sp4.aarch64.rpm",
          "libssh-debuginfo-0.9.6-21.oe2203sp4.aarch64.rpm",
          "libssh-debugsource-0.9.6-21.oe2203sp4.aarch64.rpm",
          "libssh-devel-0.9.6-21.oe2203sp4.aarch64.rpm"
        ],
        "noarch": [
          "libssh-help-0.9.6-21.oe2203sp4.noarch.rpm"
        ],
        "src": [
          "libssh-0.9.6-21.oe2203sp4.src.rpm"
        ],
        "x86_64": [
          "libssh-0.9.6-21.oe2203sp4.x86_64.rpm",
          "libssh-debuginfo-0.9.6-21.oe2203sp4.x86_64.rpm",
          "libssh-debugsource-0.9.6-21.oe2203sp4.x86_64.rpm",
          "libssh-devel-0.9.6-21.oe2203sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS-SP4",
        "name": "libssh",
        "purl": "pkg:rpm/openEuler/libssh\u0026distro=openEuler-22.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.6-21.oe2203sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "The ssh library was designed to be used by programmers needing a working SSH implementation by the mean of a library. The complete control of the client is made by the programmer. With libssh, you can remotely execute programs, transfer files, use a secure and transparent tunnel for your remote programs. With its Secure FTP implementation, you can play with remote files easily, without third-party programs others than libcrypto (from openssl).\r\n\r\nSecurity Fix(es):\n\nA flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service.(CVE-2026-59843)\n\nA flaw was found in libssh. A remote authenticated client can issue SSH_FXP_READ requests with an arbitrarily large length, causing a libssh SFTP server to allocate excessive memory and potentially exhaust it through repeated requests.(CVE-2026-59844)\n\nA flaw was found in libssh. When ProxyCommand is used, an unchecked fork() failure can be stored as process ID -1; during cleanup, signals may then be sent across the caller\u0026apos;s accessible process tree, leading to local denial of service.(CVE-2026-59845)\n\nA flaw was found in libssh. Incorrect AES-GCM finalization checks in builds using the OpenSSL backend can effectively remove integrity protection, allowing an in-path attacker to modify plaintext on the wire without detection.(CVE-2026-59847)\n\nA flaw was found in libssh. If data packets are processed after a channel is closed, channel data callbacks can be invoked after the associated data has already been freed, leading to crashes or possible use-after-free conditions.(CVE-2026-59850)",
  "id": "OESA-2026-3322",
  "modified": "2026-08-13T13:57:30Z",
  "published": "2026-08-13T13:57:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-3322"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59843"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59844"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59845"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59847"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59850"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "libssh security update",
  "upstream": [
    "CVE-2026-59843",
    "CVE-2026-59844",
    "CVE-2026-59845",
    "CVE-2026-59847",
    "CVE-2026-59850"
  ]
}



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