{
  "threat_severity" : "Important",
  "public_date" : "2026-05-07T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: \"Dirty Frag\" is a new universal Local Privilege Escalation (LPE) vulnerability in the Linux kernel",
    "id" : "2467771",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2467771"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.8",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
    "status" : "draft"
  },
  "cwe" : "CWE-123",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nxfrm: esp: avoid in-place decrypt on shared skb frags\nMSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP\nmarks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(),\nso later paths that may modify packet data can first make a private\ncopy. The IPv4/IPv6 datagram append paths did not set this flag when\nsplicing pages into UDP skbs.\nThat leaves an ESP-in-UDP packet made from shared pipe pages looking\nlike an ordinary uncloned nonlinear skb. ESP input then takes the no-COW\nfast path for uncloned skbs without a frag_list and decrypts in place\nover data that is not owned privately by the skb.\nMark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching\nTCP. Also make ESP input fall back to skb_cow_data() when the flag is\npresent, so ESP does not decrypt externally backed frags in place.\nPrivate nonlinear skb frags still use the existing fast path.\nThis intentionally does not change ESP output. In esp_output_head(),\nthe path that appends the ESP trailer to existing skb tailroom without\ncalling skb_cow_data() is not reachable for nonlinear skbs:\nskb_tailroom() returns zero when skb->data_len is nonzero, while ESP\ntailen is positive. Thus ESP output will either use the separate\ndestination-frag path or fall back to skb_cow_data().", "The “Dirty Frag” vulnerability is a local privilege escalation (LPE) issue in the Linux kernel that combines flaws in the ESP/XFRM and RXRPC subsystems to allow an unprivileged local attacker to gain root access on major Linux distributions (using any of these two: ESP/XFRM or RXRPC flaws). The attack abuses kernel page-cache manipulation and network protocol handling to overwrite privileged binaries and execute arbitrary code with elevated privileges. Exploitation differs by distribution: the ESP issue affects systems permitting unprivileged user namespaces, while the RXRPC issue impacts distributions with RXRPC enabled, such as Ubuntu. Together, the vulnerabilities provide broad cross-distribution root compromise capability, with mitigations involving disabling vulnerable kernel modules (esp4, esp6, and rxrpc) until upstream patches are fully merged and deployed." ],
  "statement" : "Dirty Frag is a deterministic Linux kernel local privilege escalation vulnerability caused by unsafe in-place cryptographic processing of shared skb fragments referencing file-backed page-cache pages in the xfrm-ESP and RxRPC paths. A low-privileged local attacker can abuse zero-copy/splice mechanisms to corrupt privileged files such as /usr/bin/su or /etc/passwd and obtain root privileges, making the issue part of the same broader bug class as Dirty Pipe and Copy Fail. The xfrm-ESP variant typically requires unprivileged user/network namespace creation, while the RxRPC variant depends on the rxrpc module being enabled or loaded, together providing broad exploitability across major Linux distributions. CVSS v3.1 is reasonably scored as 7.8 High (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H or AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H) because exploitation requires local low-privileged code execution (PR:L), does not require user interaction or race conditions (UI:N/AC:L), and successful exploitation results in full root compromise with complete confidentiality, integrity, and availability impact (C:H/I:H/A:H).",
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Under investigation",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Under investigation",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat OpenShift Container Platform 4",
    "fix_state" : "Affected",
    "package_name" : "rhcos",
    "cpe" : "cpe:/a:redhat:openshift:4"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-43284\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-43284\nhttps://dirtyfrag.io/" ],
  "csaw" : true,
  "name" : "CVE-2026-43284",
  "mitigation" : {
    "value" : "See the security bulletin for a detailed mitigation procedure.",
    "lang" : "en:us"
  }
}