ubuntu-cve-2026-5089
Vulnerability from osv_ubuntu
Published
2026-05-12 17:16
Modified
2026-05-20 21:45
Summary
Details

YAML::Syck versions before 1.38 for Perl has an out-of-bounds read. The base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When processing the leftmost segment of a colon-separated value (e.g., the 1 in 1:30:45), the inner while loop can decrement a pointer past the start of the string buffer: while ( colon >= ptr && colon != ':' ) { colon--; } if ( colon == ':' ) colon = '\0'; // colon may be ptr-1 here When no colon is found (final/leftmost segment), colon becomes ptr-1, and the subsequent colon dereference reads one byte before the allocated buffer.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libyaml-syck-perl",
            "binary_version": "1.29-1ubuntu0.16.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libyaml-syck-perl",
        "purl": "pkg:deb/ubuntu/libyaml-syck-perl@1.29-1ubuntu0.16.04.1~esm1?arch=source\u0026distro=esm-apps/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.27-2build2",
        "1.29-1",
        "1.29-1build1",
        "1.29-1ubuntu0.16.04.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libyaml-syck-perl",
            "binary_version": "1.29-1ubuntu0.18.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libyaml-syck-perl",
        "purl": "pkg:deb/ubuntu/libyaml-syck-perl@1.29-1ubuntu0.18.04.1~esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.29-1build3",
        "1.29-1ubuntu0.18.04.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libyaml-syck-perl",
            "binary_version": "1.31-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libyaml-syck-perl",
        "purl": "pkg:deb/ubuntu/libyaml-syck-perl@1.31-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.31-1",
        "1.31-1build1",
        "1.31-1ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libyaml-syck-perl",
            "binary_version": "1.34-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "libyaml-syck-perl",
        "purl": "pkg:deb/ubuntu/libyaml-syck-perl@1.34-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.34-1build1",
        "1.34-1build2",
        "1.34-1ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libyaml-syck-perl",
            "binary_version": "1.34-2ubuntu0.24.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "libyaml-syck-perl",
        "purl": "pkg:deb/ubuntu/libyaml-syck-perl@1.34-2ubuntu0.24.04.1~esm1?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.34-2",
        "1.34-2build1",
        "1.34-2build2",
        "1.34-2build3",
        "1.34-2ubuntu0.24.04.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libyaml-syck-perl",
            "binary_version": "1.34-3ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "libyaml-syck-perl",
        "purl": "pkg:deb/ubuntu/libyaml-syck-perl@1.34-3ubuntu0.1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.34-2build4",
        "1.34-3",
        "1.34-3ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libyaml-syck-perl",
            "binary_version": "1.36-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libyaml-syck-perl",
        "purl": "pkg:deb/ubuntu/libyaml-syck-perl@1.36-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.34-3",
        "1.34-4",
        "1.36-1"
      ]
    }
  ],
  "aliases": [],
  "details": "YAML::Syck versions before 1.38 for Perl  has an out-of-bounds read. The base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When processing the leftmost segment of a colon-separated value (e.g., the 1 in 1:30:45), the inner while loop can decrement a pointer past the start of the string buffer:     while ( colon \u003e= ptr \u0026\u0026 *colon != \u0027:\u0027 )     {         colon--;     }     if ( *colon == \u0027:\u0027 ) *colon = \u0027\\0\u0027;  // colon may be ptr-1 here When no colon is found (final/leftmost segment), colon becomes ptr-1, and the subsequent *colon dereference reads one byte before the allocated buffer.",
  "id": "UBUNTU-CVE-2026-5089",
  "modified": "2026-05-20T21:45:04Z",
  "published": "2026-05-12T17:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-5089"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-5089"
    },
    {
      "type": "REPORT",
      "url": "https://lists.security.metacpan.org/cve-announce/msg/39981051/"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/cpan-authors/YAML-Syck/issues/132"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/cpan-authors/YAML-Syck/pull/133"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-5089"
  ]
}



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