{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "b933ae18d9ad2a1d73c610868fcc30eb61654070"
            }
          ],
          "repo": "https://github.com/freerdp/freerdp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-mr6w-ch7c-mqqj"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-787"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26955.json"
  },
  "details": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., `xfreerdp`) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination rectangle. The `gdi_SurfaceCommand_ClearCodec()` handler does not call `is_within_surface()` to validate the command rectangle against the destination surface dimensions, allowing attacker-controlled `cmd-\u003eleft`/`cmd-\u003etop` (and subcodec rectangle offsets) to reach image copy routines that write into `surface-\u003edata` without bounds enforcement. The OOB write corrupts an adjacent `gdiGfxSurface` struct's `codecs*` pointer with attacker-controlled pixel data, and corruption of `codecs*` is sufficient to reach an indirect function pointer call (`NSC_CONTEXT.decode` at `nsc.c:500`) on a subsequent codec command — full instruction pointer (RIP) control demonstrated in exploitability harness. Users should upgrade to version 3.23.0 to receive a patch.",
  "id": "CVE-2026-26955",
  "modified": "2026-04-01T23:10:39.877335897Z",
  "published": "2026-02-25T20:47:14.660Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26955.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mr6w-ch7c-mqqj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-26955"
    },
    {
      "type": "FIX",
      "url": "https://github.com/FreeRDP/FreeRDP/commit/7d8fdce2d0ef337cb86cb37fc0c436c905e04d77"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "FreeRDP has Out-of-bounds Write"
}