ubuntu-cve-2026-6691
Vulnerability from osv_ubuntu
Published
2026-05-06 16:16
Modified
2026-05-14 11:38
Summary
Details

The MongoDB C Driver's Cyrus SASL integration performs unsafe string copying during username canonicalization, enabling a heap buffer overflow before any authentication or network traffic. This may be triggered by passing untrusted input in the username of a MongoDB URI with authMechanism=GSSAPI.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.6 (High)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libbson-1.0-0",
            "binary_version": "1.16.1-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "libmongoc-1.0-0",
            "binary_version": "1.16.1-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "mongo-c-driver",
        "purl": "pkg:deb/ubuntu/mongo-c-driver@1.16.1-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.15.0-1",
        "1.15.1-1",
        "1.15.2-1",
        "1.16.0-1",
        "1.16.1-1",
        "1.16.1-1build1",
        "1.16.1-1build2",
        "1.16.1-1ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libbson-1.0-0",
            "binary_version": "1.21.0-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "libmongoc-1.0-0",
            "binary_version": "1.21.0-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "mongo-c-driver",
        "purl": "pkg:deb/ubuntu/mongo-c-driver@1.21.0-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.18.0-1",
        "1.19.1-1",
        "1.19.2-1",
        "1.20.0-1",
        "1.20.0-1build1",
        "1.20.1-1",
        "1.21.0-1",
        "1.21.0-1build1",
        "1.21.0-1ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libbson-1.0-0t64",
            "binary_version": "1.26.0-1.1ubuntu2+esm1"
          },
          {
            "binary_name": "libmongoc-1.0-0t64",
            "binary_version": "1.26.0-1.1ubuntu2+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "mongo-c-driver",
        "purl": "pkg:deb/ubuntu/mongo-c-driver@1.26.0-1.1ubuntu2+esm1?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.24.3-1",
        "1.24.4-1",
        "1.25.1-1",
        "1.25.2-1",
        "1.25.4-1",
        "1.26.0-1",
        "1.26.0-1.1ubuntu1",
        "1.26.0-1.1ubuntu2",
        "1.26.0-1.1ubuntu2+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libbson-1.0-0t64",
            "binary_version": "1.30.4-1ubuntu1"
          },
          {
            "binary_name": "libmongoc-1.0-0t64",
            "binary_version": "1.30.4-1ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "mongo-c-driver",
        "purl": "pkg:deb/ubuntu/mongo-c-driver@1.30.4-1ubuntu1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.30.2-1",
        "1.30.4-1ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "The MongoDB C Driver\u0027s Cyrus SASL integration performs unsafe string copying during username canonicalization, enabling a heap buffer overflow before any authentication or network traffic. This may be triggered by passing untrusted input in the username of a MongoDB URI with authMechanism=GSSAPI.",
  "id": "UBUNTU-CVE-2026-6691",
  "modified": "2026-05-14T11:38:31Z",
  "published": "2026-05-06T16:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-6691"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-6691"
    },
    {
      "type": "REPORT",
      "url": "https://jira.mongodb.org/browse/CDRIVER-6134"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/mongodb/mongo-c-driver/commit/b4984965877d559862e225beba09cb4e9d4a56a6"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/mongodb/mongo-c-driver/commit/d9c26f49e75d3de746a690db9c81ff5b4f6e21b0"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-6691"
  ]
}



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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.