{
  "cveId": "CVE-2026-45990",
  "url": "https://patchblox.com/security/cve/CVE-2026-45990",
  "summary": "CVE-2026-45990 is fixed in 19 products on 1 platform, first by ALAS2023-2026-1754, released May 25, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  slub: fix data loss and overflow in krealloc()...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  slub: fix data loss and overflow in krealloc()  Commit 2cd8231796b5 (\u0022mm/slub: allow to set node and align in k[v]realloc\u0022) introduced the ability to force a reallocation if the original object does not satisfy new alignment or NUMA node, even when the object is being shrunk.  This introduced two bugs in the reallocation fallback path:  1. Data loss during NUMA migration: The jump to \u0027alloc_new\u0027 happens    before \u0027ks\u0027 and \u0027orig_size\u0027 are initialized. As a result, the    memcpy() in the \u0027alloc_new\u0027 block would copy 0 bytes into the new    allocation.  2. Buffer overflow during shrinking: When shrinking an object while    forcing a new alignment, \u0027new_size\u0027 is smaller than the old size.    However, the memcpy() used the old size (\u0027orig_size ?: ks\u0027), leading    to an out-of-bounds write.  The same overflow bug exists in the kvrealloc() fallback path, where the old bucket size ksize(p) is copied into the new buffer without being bounded by the new size.  A simple reproducer:  \t// e.g. add to lkdtm as KREALLOC_SHRINK_OVERFLOW \twhile (1) { \t\tvoid *p = kmalloc(128, GFP_KERNEL); \t\tp = krealloc_node_align(p, 64, 256, GFP_KERNEL, NUMA_NO_NODE); \t\tkfree(p); \t}  demonstrates the issue:    ==================================================================   BUG: KFENCE: out-of-bounds write in memcpy_orig\u002B0x68/0x130    Out-of-bounds write at 0xffff8883ad757038 (120B right of kfence-#47):    memcpy_orig\u002B0x68/0x130    krealloc_node_align_noprof\u002B0x1c8/0x340    lkdtm_KREALLOC_SHRINK_OVERFLOW\u002B0x8c/0xc0 [lkdtm]    lkdtm_do_action\u002B0x3a/0x60 [lkdtm]    ...    kfence-#47: 0xffff8883ad756fc0-0xffff8883ad756fff, size=64, cache=kmalloc-64    allocated by task 316 on cpu 7 at 97.680481s (0.021813s ago):    krealloc_node_align_noprof\u002B0x19c/0x340    lkdtm_KREALLOC_SHRINK_OVERFLOW\u002B0x8c/0xc0 [lkdtm]    lkdtm_do_action\u002B0x3a/0x60 [lkdtm]    ...   ==================================================================  Fix it by moving the old size calculation to the top of __do_krealloc() and bounding all copy lengths by the new allocation size.",
  "published": "2026-05-25T09:00:00Z",
  "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": 0.00133,
  "epssPercentile": 0.02878,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "bpftool6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "bpftool6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel-livepatch-6.18.30-61.116",
      "release": "amzn 2023",
      "fixedVersion": "1:1.0-0.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-aarch64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-x86_64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-headers",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra-common",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.4-1",
      "fix": "DEBIAN-CVE-2026-45990",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-45990",
      "released": "2026-05-27T17:38:13Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.30-61.116.amzn2023",
      "fix": "ALAS2023-2026-1754",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754",
      "released": "2026-05-25T09:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}