{
  "cveId": "CVE-2026-98061",
  "url": "https://patchblox.com/security/cve/CVE-2026-98061",
  "summary": "CVE-2026-98061 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-98061, released October 2, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  bpf: Reject tail calls directly from callback fr...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  bpf: Reject tail calls directly from callback frames  A tail call from a non-zero frame is modeled as a return from that frame. The verifier makes R0 unknown and calls prepare_func_exit() for the taken branch.  When the current frame is a synchronous callback, prepare_func_exit() enforces the callback return-value contract and marks R0 precise. Since the tail-call path synthesized R0 rather than deriving it from an instruction, precision backtracking reaches the callback-calling instruction with R0 still requested and triggers the \u0022callback unexpected regs\u0022 verifier bug. A CAP_BPF task can therefore cause a WARN and an -EFAULT BPF_PROG_LOAD.  Tail calls reachable from callbacks are already rejected later by check_max_stack_depth(). Reject a tail call made directly by a callback before constructing the inconsistent return state, using the existing diagnostic. Tail calls from ordinary subprograms keep their current behavior.",
  "published": "2026-09-25T11:17:35Z",
  "severity": "important",
  "epss": 0.00198,
  "epssPercentile": 0.09666,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "bpftool6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "bpftool6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel-livepatch-6.18.54-121.166",
      "release": "amzn 2023",
      "fixedVersion": "1:1.0-0.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-aarch64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-x86_64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-headers",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra-common",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.7-1",
      "fix": "DEBIAN-CVE-2026-98061",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-98061",
      "released": "2026-10-02T21:04:56Z"
    },
    {
      "platform": "linux",
      "product": "microvm-kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}