{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6"
            },
            {
              "fixed": "cb3beef35ab5e0c1afca9fd7648c6ae499786377"
            },
            {
              "fixed": "ba758fdf1399f310b30098b6faa3fd043de47dd2"
            },
            {
              "fixed": "fcca1df05322bb04e344dd1178b54b76a08eb7c3"
            },
            {
              "fixed": "8a5e840babc5c0fbd10c73728a13192347771ec6"
            },
            {
              "fixed": "49e41b60ccd1bdbe9e218420f716dd5f9a2f9c71"
            },
            {
              "fixed": "0cab5d077dd1efd2bd1a47271acc35894f945b4f"
            },
            {
              "fixed": "2b5c3c040d020e3ab3b9a8887031202d96843b1e"
            },
            {
              "fixed": "cc1ff87bce1ccd38410ab10960f576dcd17db679"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0.0"
            },
            {
              "fixed": "5.10.258"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.209"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.175"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.141"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.91"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.33"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53003.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\npppoe: drop PFC frames\n\nRFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT\nRECOMMENDED for PPPoE. In practice, pppd does not support negotiating\nPFC for PPPoE sessions, and the current PPPoE driver assumes an\nuncompressed (2-byte) protocol field. However, the generic PPP layer\nfunction ppp_input() is not aware of the negotiation result, and still\naccepts PFC frames.\n\nIf a peer with a broken implementation or an attacker sends a frame with\na compressed (1-byte) protocol field, the subsequent PPP payload is\nshifted by one byte. This causes the network header to be 4-byte\nmisaligned, which may trigger unaligned access exceptions on some\narchitectures.\n\nTo reduce the attack surface, drop PPPoE PFC frames. Introduce\nppp_skb_is_compressed_proto() helper function to be used in both\nppp_generic.c and pppoe.c to avoid open-coding.",
  "id": "CVE-2026-53003",
  "modified": "2026-08-06T03:30:59.015458672Z",
  "published": "2026-06-24T16:29:15.268Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0cab5d077dd1efd2bd1a47271acc35894f945b4f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2b5c3c040d020e3ab3b9a8887031202d96843b1e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/49e41b60ccd1bdbe9e218420f716dd5f9a2f9c71"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8a5e840babc5c0fbd10c73728a13192347771ec6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ba758fdf1399f310b30098b6faa3fd043de47dd2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cb3beef35ab5e0c1afca9fd7648c6ae499786377"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cc1ff87bce1ccd38410ab10960f576dcd17db679"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fcca1df05322bb04e344dd1178b54b76a08eb7c3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53003.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53003"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "pppoe: drop PFC frames"
}