{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-43500",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-43500"
  ],
  "published": "2026-05-11T06:27:03Z",
  "summary": "rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Also unshare DATA/RESPONSE packets when paged frags are present\n\nThe DATA-packet handler in rxrpc_input_call_event() and the RESPONSE\nhandler in rxrpc_verify_response() copy the skb to a linear one before\ncalling into the security ops only when skb_cloned() is true.  An skb\nthat is not cloned but still carries externally-owned paged fragments\n(e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via\n__ip_append_data, or a chained skb_has_frag_list()) falls through to\nthe in-place decryption path, which binds the frag pages directly into\nthe AEAD/skcipher SGL via skb_to_sgvec().\n\nExtend the gate to also unshare when skb_has_frag_list() or\nskb_has_shared_frag() is true.  This catches the splice-loopback vector\nand other externally-shared frag sources while preserving the\nzero-copy fast path for skbs whose frags are kernel-private (e.g. NIC\npage_pool RX, GRO).  The OOM/trace handling already in place is reused.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-43500"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7c504ffab3efce8f7e4f463b314ae31030bdf18b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3711382a77342a9a1c3d2e7330dcfc7ea927f568"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3eae0f4f9f7206a4801efa5e0235c25bbd5a412c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d45179f8795222ce858770dc619abe51f9d24411"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/aa54b1d27fe0c2b78e664a34fd0fdf7cd1960d71"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T13:16:28Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The exploitable shared-fragment condition is created locally by sending RxRPC-shaped UDP data with splice/vmsplice/sendfile-backed pages into the local receive path; ordinary remote packets do not provide attacker-owned page frags on the receiver.\nAC:L - No race or hard-to-control timing is required; an attacker can construct the packet shape and encrypted contents needed to reach the in-place decryption path.\nPR:L - The attacker needs local code execution to create sockets and use splice-backed UDP transmission, but AF_RXRPC socket creation and the relevant send path do not require administrative privileges.\nUI:N - After the local attacker runs code, exploitation does not require a victim user to open files, mount filesystems, or take any other action.\nS:U - The vulnerability affects kernel memory/page-cache handling within the same host security authority and is not a VM, IOMMU, or sandbox boundary escape by itself.\nC:H - The bug is a memory/page-cache corruption primitive caused by decrypting directly into externally owned skb fragments, and successful privilege escalation would allow broad disclosure of protected data.\nI:H - The attacker can influence plaintext written by in-place decryption into shared backing pages, making high-impact data modification and privilege escalation defensible.\nA:H - Corrupting shared packet/page backing storage can destabilize kernel consumers or corrupt critical data, making kernel crash or severe service disruption plausible."
    }
  }
}