{
  "cveId": "CVE-2026-31691",
  "url": "https://patchblox.com/security/cve/CVE-2026-31691",
  "summary": "CVE-2026-31691 is fixed in 19 products on 1 platform, first by ALAS2023-2026-1693, released May 8, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  igb: remove napi_synchronize() in igb_down()  Wh...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  igb: remove napi_synchronize() in igb_down()  When an AF_XDP zero-copy application terminates abruptly (e.g., kill -9), the XSK buffer pool is destroyed but NAPI polling continues. igb_clean_rx_irq_zc() repeatedly returns the full budget, preventing napi_complete_done() from clearing NAPI_STATE_SCHED.  igb_down() calls napi_synchronize() before napi_disable() for each queue vector. napi_synchronize() spins waiting for NAPI_STATE_SCHED to clear, which never happens. igb_down() blocks indefinitely, the TX watchdog fires, and the TX queue remains permanently stalled.  napi_disable() already handles this correctly: it sets NAPI_STATE_DISABLE. After a full-budget poll, __napi_poll() checks napi_disable_pending(). If set, it forces completion and clears NAPI_STATE_SCHED, breaking the loop that napi_synchronize() cannot.  napi_synchronize() was added in commit 41f149a285da (\u0022igb: Fix possible panic caused by Rx traffic arrival while interface is down\u0022). napi_disable() provides stronger guarantees: it prevents further scheduling and waits for any active poll to exit. Other Intel drivers (ixgbe, ice, i40e) use napi_disable() without a preceding napi_synchronize() in their down paths.  Remove redundant napi_synchronize() call and reorder napi_disable() before igb_set_queue_napi() so the queue-to-NAPI mapping is only cleared after polling has fully stopped.",
  "published": "2026-04-27T18:16:54Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00112,
  "epssPercentile": 0.01403,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "bpftool6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "bpftool6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel-livepatch-6.18.25-55.108",
      "release": "amzn 2023",
      "fixedVersion": "1:1.0-0.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-aarch64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-x86_64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-headers",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra-common",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.19.13-1",
      "fix": "DEBIAN-CVE-2026-31691",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31691",
      "released": "2026-05-15T16:01:09Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.25-55.108.amzn2023",
      "fix": "ALAS2023-2026-1693",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1693",
      "released": "2026-05-08T18:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}