ubuntu-cve-2026-39956
Vulnerability from osv_ubuntu
Published
2026-04-13 23:16
Modified
2026-05-20 15:27
Summary
Details

jq is a command-line JSON processor. In commits after 69785bf77f86e2ea1b4a20ca86775916889e91c9, the _strindices builtin in jq's src/builtin.c passes its arguments directly to jv_string_indexes() without verifying they are strings, and jv_string_indexes() in src/jv.c relies solely on assert() checks that are stripped in release builds compiled with -DNDEBUG. This allows an attacker to crash jq trivially with input like _strindices(0), and by crafting a numeric value whose IEEE-754 bit pattern maps to a chosen pointer, achieve a controlled pointer dereference and limited memory read/probe primitive. Any deployment that evaluates untrusted jq filters against a release build is vulnerable. This issue has been patched in commit fdf8ef0f0810e3d365cdd5160de43db46f57ed03.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "jq",
            "binary_version": "1.5+dfsg-1ubuntu0.1+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "jq",
        "purl": "pkg:deb/ubuntu/jq@1.5+dfsg-1ubuntu0.1+esm4?arch=source\u0026distro=esm-apps/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5+dfsg-1ubuntu0.1+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4-2.1",
        "1.5+dfsg-1",
        "1.5+dfsg-1ubuntu0.1",
        "1.5+dfsg-1ubuntu0.1+esm2",
        "1.5+dfsg-1ubuntu0.1+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "jq",
            "binary_version": "1.5+dfsg-2ubuntu0.1~esm2"
          },
          {
            "binary_name": "libjq1",
            "binary_version": "1.5+dfsg-2ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "jq",
        "purl": "pkg:deb/ubuntu/jq@1.5+dfsg-2ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5+dfsg-2ubuntu0.1~esm2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5+dfsg-2",
        "1.5+dfsg-2ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "jq",
            "binary_version": "1.6-1ubuntu0.20.04.1+esm2"
          },
          {
            "binary_name": "libjq1",
            "binary_version": "1.6-1ubuntu0.20.04.1+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "jq",
        "purl": "pkg:deb/ubuntu/jq@1.6-1ubuntu0.20.04.1+esm2?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6-1ubuntu0.20.04.1+esm2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5+dfsg-2build1",
        "1.6-1",
        "1.6-1ubuntu0.20.04.1",
        "1.6-1ubuntu0.20.04.1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "jq",
            "binary_version": "1.6-2.1ubuntu3.2"
          },
          {
            "binary_name": "libjq1",
            "binary_version": "1.6-2.1ubuntu3.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "jq",
        "purl": "pkg:deb/ubuntu/jq@1.6-2.1ubuntu3.2?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6-2.1ubuntu3.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6-2.1ubuntu2",
        "1.6-2.1ubuntu3",
        "1.6-2.1ubuntu3.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "jq",
            "binary_version": "1.7.1-3ubuntu0.24.04.2"
          },
          {
            "binary_name": "libjq1",
            "binary_version": "1.7.1-3ubuntu0.24.04.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "jq",
        "purl": "pkg:deb/ubuntu/jq@1.7.1-3ubuntu0.24.04.2?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.7.1-3ubuntu0.24.04.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6-3",
        "1.7-1",
        "1.7.1-2",
        "1.7.1-3",
        "1.7.1-3build1",
        "1.7.1-3ubuntu0.24.04.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "jq",
            "binary_version": "1.8.1-3ubuntu1.1"
          },
          {
            "binary_name": "libjq1",
            "binary_version": "1.8.1-3ubuntu1.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "jq",
        "purl": "pkg:deb/ubuntu/jq@1.8.1-3ubuntu1.1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.1-3ubuntu1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.7.1-3ubuntu1",
        "1.7.1-6ubuntu1",
        "1.8.1-3ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "jq",
            "binary_version": "1.8.1-4ubuntu2"
          },
          {
            "binary_name": "libjq1",
            "binary_version": "1.8.1-4ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "jq",
        "purl": "pkg:deb/ubuntu/jq@1.8.1-4ubuntu2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.1-4ubuntu2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.1-3ubuntu1",
        "1.8.1-4ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "jq is a command-line JSON processor. In commits after 69785bf77f86e2ea1b4a20ca86775916889e91c9, the _strindices builtin in jq\u0027s src/builtin.c passes its arguments directly to jv_string_indexes() without verifying they are strings, and jv_string_indexes() in src/jv.c relies solely on assert() checks that are stripped in release builds compiled with -DNDEBUG. This allows an attacker to crash jq trivially with input like _strindices(0), and by crafting a numeric value whose IEEE-754 bit pattern maps to a chosen pointer, achieve a controlled pointer dereference and limited memory read/probe primitive. Any deployment that evaluates untrusted jq filters against a release build is vulnerable. This issue has been patched in commit fdf8ef0f0810e3d365cdd5160de43db46f57ed03.",
  "id": "UBUNTU-CVE-2026-39956",
  "modified": "2026-05-20T15:27:25Z",
  "published": "2026-04-13T23:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-39956"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-39956"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jqlang/jq/security/advisories/GHSA-6gc3-3g9p-xx28"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jqlang/jq/commit/fdf8ef0f0810e3d365cdd5160de43db46f57ed03"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8202-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8202-2"
    }
  ],
  "related": [
    "USN-8202-1",
    "USN-8202-2"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-39956"
  ]
}



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