CVE-2026-33416

{
  "id": "CVE-2026-33416",
  "cveTags": [],
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          "id": "CVE-2026-33416",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
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              "automatable": "no"
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            {
              "technicalImpact": "total"
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          "version": "2.0.3",
          "timestamp": "2026-03-31T00:00:00+00:00"
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          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "REQUIRED",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
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        "impactScore": 5.9,
        "exploitabilityScore": 1.6
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  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "pnggroup",
          "product": "libpng",
          "versions": [
            {
              "status": "affected",
              "version": ">= 1.2.1, < 1.6.56"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-03-26T17:16:38.443",
  "references": [
    {
      "url": "https://github.com/pnggroup/libpng/commit/23019269764e35ed8458e517f1897bd3c54820eb",
      "tags": [
        "Patch"
      ],
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    {
      "url": "https://github.com/pnggroup/libpng/commit/7ea9eea884a2328cc7fdcb3c0c00246a50d90667",
      "tags": [
        "Patch"
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    {
      "url": "https://github.com/pnggroup/libpng/commit/a3a21443ed12bfa1ef46fa0d4fb2b74a0fa34a25",
      "tags": [
        "Patch"
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    {
      "url": "https://github.com/pnggroup/libpng/commit/c1b0318b393c90679e6fa5bc1d329fd5d5012ec1",
      "tags": [
        "Patch"
      ],
      "source": "security-advisories@github.com"
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    {
      "url": "https://github.com/pnggroup/libpng/pull/824",
      "tags": [
        "Exploit",
        "Issue Tracking"
      ],
      "source": "security-advisories@github.com"
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    {
      "url": "https://github.com/pnggroup/libpng/security/advisories/GHSA-m4pc-p4q3-4c7j",
      "tags": [
        "Patch",
        "Vendor Advisory"
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  "vulnStatus": "Analyzed",
  "weaknesses": [
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      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.2.1 through 1.6.55, `png_set_tRNS` and `png_set_PLTE` each alias a heap-allocated buffer between `png_struct` and `png_info`, sharing a single allocation across two structs with independent lifetimes. The `trans_alpha` aliasing has been present since at least libpng 1.0, and the `palette` aliasing since at least 1.2.1. Both affect all prior release lines `png_set_tRNS` sets `png_ptr->trans_alpha = info_ptr->trans_alpha` (256-byte buffer) and `png_set_PLTE` sets `info_ptr->palette = png_ptr->palette` (768-byte buffer). In both cases, calling `png_free_data` (with `PNG_FREE_TRNS` or `PNG_FREE_PLTE`) frees the buffer through `info_ptr` while the corresponding `png_ptr` pointer remains dangling. Subsequent row-transform functions dereference and, in some code paths, write to the freed memory. A second call to `png_set_tRNS` or `png_set_PLTE` has the same effect, because both functions call `png_free_data` internally before reallocating the `info_ptr` buffer. Version 1.6.56 fixes the issue."
    },
    {
      "lang": "es",
      "value": "LIBPNG es una biblioteca de referencia para su uso en aplicaciones que leen, crean y manipulan archivos de imagen ráster PNG (Portable Network Graphics). En las versiones 1.2.1 a 1.6.55, 'png_set_tRNS' y 'png_set_PLTE' cada una aliasan un búfer asignado en el heap entre 'png_struct' y 'png_info', compartiendo una única asignación entre dos estructuras con vidas útiles independientes. El aliasing de 'trans_alpha' ha estado presente desde al menos libpng 1.0, y el aliasing de 'palette' desde al menos 1.2.1. Ambos afectan a todas las líneas de versiones anteriores: 'png_set_tRNS' establece 'png_ptr-&gt;trans_alpha = info_ptr-&gt;trans_alpha' (búfer de 256 bytes) y 'png_set_PLTE' establece 'info_ptr-&gt;palette = png_ptr-&gt;palette' (búfer de 768 bytes). En ambos casos, llamar a 'png_free_data' (con 'PNG_FREE_TRNS' o 'PNG_FREE_PLTE') libera el búfer a través de 'info_ptr' mientras que el puntero 'png_ptr' correspondiente permanece colgante. Las funciones de transformación de fila subsiguientes desreferencian y, en algunas rutas de código, escriben en la memoria liberada. Una segunda llamada a 'png_set_tRNS' o 'png_set_PLTE' tiene el mismo efecto, porque ambas funciones llaman internamente a 'png_free_data' antes de reasignar el búfer de 'info_ptr'. La versión 1.6.56 corrige el problema."
    }
  ],
  "lastModified": "2026-06-17T10:37:27.583",
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