UBUNTU-CVE-2026-91926 (CVE-2026-91926)

Vulnerability from osv_ubuntu – Published: 2026-09-15 12:17 – Updated: 2026-09-23 23:39 – Source website
VLAI
Details

A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info parser when a crafted NTLM CHALLENGE message contains duplicated string-valued AV_PAIR entries. The parser allocates memory for each string value but does not free the previous allocation when the same AV_PAIR type appears more than once, leaking the earlier allocation. A malicious or man-in-the-middle server can exploit this to cause gradual memory exhaustion on the client during NTLM authentication, leading to a denial of service.

Severity
3.7 (Low)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "gss-ntlmssp",
            "binary_version": "0.7.0-3~ubuntu0.16.04.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "gss-ntlmssp",
        "purl": "pkg:deb/ubuntu/gss-ntlmssp@0.7.0-3~ubuntu0.16.04.1+esm1?arch=source\u0026distro=esm-apps/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.6.0-1",
        "0.7.0-3~ubuntu0.16.04.1",
        "0.7.0-3~ubuntu0.16.04.1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "gss-ntlmssp",
            "binary_version": "0.7.0-4ubuntu0.18.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "gss-ntlmssp",
        "purl": "pkg:deb/ubuntu/gss-ntlmssp@0.7.0-4ubuntu0.18.04.1~esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.7.0-3",
        "0.7.0-4",
        "0.7.0-4build1",
        "0.7.0-4build3",
        "0.7.0-4ubuntu0.18.04.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "gss-ntlmssp",
            "binary_version": "0.7.0-4ubuntu0.20.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "gss-ntlmssp",
        "purl": "pkg:deb/ubuntu/gss-ntlmssp@0.7.0-4ubuntu0.20.04.1~esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.7.0-4build3",
        "0.7.0-4ubuntu0.20.04.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "gss-ntlmssp",
            "binary_version": "0.7.0-4ubuntu0.22.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "gss-ntlmssp",
        "purl": "pkg:deb/ubuntu/gss-ntlmssp@0.7.0-4ubuntu0.22.04.1~esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.7.0-4build3",
        "0.7.0-4build4",
        "0.7.0-4ubuntu0.22.04.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "gss-ntlmssp",
            "binary_version": "1.2.0-1build3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "gss-ntlmssp",
        "purl": "pkg:deb/ubuntu/gss-ntlmssp@1.2.0-1build3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.0-1",
        "1.2.0-1build1",
        "1.2.0-1build2",
        "1.2.0-1build3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "gss-ntlmssp",
            "binary_version": "1.2.0-1build5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "gss-ntlmssp",
        "purl": "pkg:deb/ubuntu/gss-ntlmssp@1.2.0-1build5?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.0-1build4",
        "1.2.0-1build5"
      ]
    }
  ],
  "aliases": [],
  "details": "A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info parser when a crafted NTLM CHALLENGE message contains duplicated string-valued AV_PAIR entries. The parser allocates memory for each string value but does not free the previous allocation when the same AV_PAIR type appears more than once, leaking the earlier allocation. A malicious or man-in-the-middle server can exploit this to cause gradual memory exhaustion on the client during NTLM authentication, leading to a denial of service.",
  "id": "UBUNTU-CVE-2026-91926",
  "modified": "2026-09-23T23:39:29Z",
  "published": "2026-09-15T12:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-91926"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-91926"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2533698"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-91926"
  ]
}



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