{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "b00402d3258402c868224b6ffed04182cbed78d9"
            }
          ],
          "repo": "https://github.com/freerdp/freerdp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-85x9-4xxp-xhm5"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-122",
      "CWE-191"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31883.json"
  },
  "details": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server) is set such that size % block_size == 0 triggers the header parsing at a point where size is smaller than the header (4 or 8 bytes), the subtraction wraps size to ~SIZE_MAX. The while (size \u003e 0) loop then continues for an astronomical number of iterations. This vulnerability is fixed in 3.24.0.",
  "id": "CVE-2026-31883",
  "modified": "2026-04-01T23:08:13.219938753Z",
  "published": "2026-03-13T17:35:17.411Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31883.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31883"
    },
    {
      "type": "FIX",
      "url": "https://github.com/FreeRDP/FreeRDP/commit/16df2300e1e3f5a51f68fb1626429e58b531b7c8"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "FreeRDP has a `size_t` underflow in ADPCM decoder leads to heap-buffer-overflow write"
}