GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration
ubuntu-cve-2026-34757
Vulnerability from osv_ubuntu
Published
2026-04-09 15:16
Modified
2026-08-18 19:33
Summary
Details

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaking unrelated heap contents into the chunk struct). This vulnerability is fixed in 1.6.57.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libpng12-0",
            "binary_version": "1.2.50-1ubuntu2.14.04.3+esm2"
          },
          {
            "binary_name": "libpng3",
            "binary_version": "1.2.50-1ubuntu2.14.04.3+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libpng",
        "purl": "pkg:deb/ubuntu/libpng@1.2.50-1ubuntu2.14.04.3+esm2?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.50-1ubuntu2.14.04.3+esm2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.49-4ubuntu1",
        "1.2.49-5ubuntu1",
        "1.2.50-1ubuntu1",
        "1.2.50-1ubuntu2",
        "1.2.50-1ubuntu2.14.04.1",
        "1.2.50-1ubuntu2.14.04.2",
        "1.2.50-1ubuntu2.14.04.3",
        "1.2.50-1ubuntu2.14.04.3+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libpng12-0",
            "binary_version": "1.2.54-1ubuntu1.1+esm3"
          },
          {
            "binary_name": "libpng3",
            "binary_version": "1.2.54-1ubuntu1.1+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libpng",
        "purl": "pkg:deb/ubuntu/libpng@1.2.54-1ubuntu1.1+esm3?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.54-1ubuntu1.1+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.51-0ubuntu3",
        "1.2.54-1",
        "1.2.54-1ubuntu1",
        "1.2.54-1ubuntu1.1",
        "1.2.54-1ubuntu1.1+esm1",
        "1.2.54-1ubuntu1.1+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libpng16-16",
            "binary_version": "1.6.20-2ubuntu0.1~esm4"
          },
          {
            "binary_name": "libpng16-devtools",
            "binary_version": "1.6.20-2ubuntu0.1~esm4"
          },
          {
            "binary_name": "libpng16-tools",
            "binary_version": "1.6.20-2ubuntu0.1~esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libpng1.6",
        "purl": "pkg:deb/ubuntu/libpng1.6@1.6.20-2ubuntu0.1~esm4?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6.20-2ubuntu0.1~esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.20-2",
        "1.6.20-2ubuntu0.1~esm1",
        "1.6.20-2ubuntu0.1~esm2",
        "1.6.20-2ubuntu0.1~esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libpng-tools",
            "binary_version": "1.6.34-1ubuntu0.18.04.2+esm3"
          },
          {
            "binary_name": "libpng16-16",
            "binary_version": "1.6.34-1ubuntu0.18.04.2+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libpng1.6",
        "purl": "pkg:deb/ubuntu/libpng1.6@1.6.34-1ubuntu0.18.04.2+esm3?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6.34-1ubuntu0.18.04.2+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.34-1",
        "1.6.34-1ubuntu0.18.04.1",
        "1.6.34-1ubuntu0.18.04.2",
        "1.6.34-1ubuntu0.18.04.2+esm1",
        "1.6.34-1ubuntu0.18.04.2+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libpng-tools",
            "binary_version": "1.6.37-2ubuntu0.1~esm3"
          },
          {
            "binary_name": "libpng16-16",
            "binary_version": "1.6.37-2ubuntu0.1~esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libpng1.6",
        "purl": "pkg:deb/ubuntu/libpng1.6@1.6.37-2ubuntu0.1~esm3?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6.37-2ubuntu0.1~esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.37-1",
        "1.6.37-2",
        "1.6.37-2ubuntu0.1~esm1",
        "1.6.37-2ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libpng-tools",
            "binary_version": "1.6.37-3ubuntu0.5"
          },
          {
            "binary_name": "libpng16-16",
            "binary_version": "1.6.37-3ubuntu0.5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libpng1.6",
        "purl": "pkg:deb/ubuntu/libpng1.6@1.6.37-3ubuntu0.5?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6.37-3ubuntu0.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.37-3build4",
        "1.6.37-3build5",
        "1.6.37-3ubuntu0.1",
        "1.6.37-3ubuntu0.3",
        "1.6.37-3ubuntu0.4"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libpng-tools",
            "binary_version": "1.6.43-5ubuntu0.6"
          },
          {
            "binary_name": "libpng16-16t64",
            "binary_version": "1.6.43-5ubuntu0.6"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libpng1.6",
        "purl": "pkg:deb/ubuntu/libpng1.6@1.6.43-5ubuntu0.6?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6.43-5ubuntu0.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.40-1",
        "1.6.40-2",
        "1.6.40-3",
        "1.6.42-1",
        "1.6.43-1",
        "1.6.43-3",
        "1.6.43-5build1",
        "1.6.43-5ubuntu0.1",
        "1.6.43-5ubuntu0.3",
        "1.6.43-5ubuntu0.4",
        "1.6.43-5ubuntu0.5"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libpng-tools",
            "binary_version": "1.6.50-1ubuntu0.5"
          },
          {
            "binary_name": "libpng16-16t64",
            "binary_version": "1.6.50-1ubuntu0.5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "libpng1.6",
        "purl": "pkg:deb/ubuntu/libpng1.6@1.6.50-1ubuntu0.5?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6.50-1ubuntu0.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.47-1.1",
        "1.6.48-1",
        "1.6.49-1~exp1",
        "1.6.50-1~exp1",
        "1.6.50-1",
        "1.6.50-1ubuntu0.1",
        "1.6.50-1ubuntu0.3",
        "1.6.50-1ubuntu0.4"
      ]
    }
  ],
  "aliases": [],
  "details": "LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaking unrelated heap contents into the chunk struct). This vulnerability is fixed in 1.6.57.",
  "id": "UBUNTU-CVE-2026-34757",
  "modified": "2026-08-18T19:33:06Z",
  "published": "2026-04-09T15:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-34757"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-34757"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pnggroup/libpng/security/advisories/GHSA-6fr7-g8h7-v645"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8251-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8639-1"
    }
  ],
  "related": [
    "USN-8251-1",
    "USN-8639-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-34757"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • 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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.