{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "ddc7c3042614e273044f698d2beab25cc3842d45"
            },
            {
              "fixed": "a9e777f856cd2f1efc106afc7bf21aef868509d5"
            },
            {
              "fixed": "669349b4612c26b3d7aacfa99d7174681bd19223"
            },
            {
              "fixed": "3ff85ae79e1a74baeb916b78a63d821f6d19a994"
            },
            {
              "fixed": "36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a"
            },
            {
              "fixed": "76f2ebaf79a9ae6d0737b87f045fe769e425d78f"
            },
            {
              "fixed": "99dbab7b5a12d8f58d5b0aa2f7a1fe656a70f4b2"
            },
            {
              "fixed": "1c22483a2c4bbf747787f328392ca3e68619c4dc"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.4.0"
            },
            {
              "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/2026/45xxx/CVE-2026-45839.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()\n\nCO-RE accessor strings are colon-separated indices that describe a path\nfrom a root BTF type to a target field, e.g. \"0:1:2\" walks through\nnested struct members. bpf_core_parse_spec() parses each component with\nsscanf(\"%d\"), so negative values like -1 are silently accepted.  The\nsubsequent bounds checks (access_idx \u003e= btf_vlen(t)) only guard the\nupper bound and always pass for negative values because C integer\npromotion converts the __u16 btf_vlen result to int, making the\ncomparison (int)(-1) \u003e= (int)(N) false for any positive N.\n\nWhen -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,\nproducing an out-of-bounds read far past the members array.  A crafted\nBPF program with a negative CO-RE accessor on any struct that exists in\nvmlinux BTF (e.g. task_struct) crashes the kernel deterministically\nduring BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y\n(default on major distributions).  The bug is reachable with CAP_BPF:\n\n BUG: unable to handle page fault for address: ffffed11818b6626\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n Oops: Oops: 0000 [#1] SMP KASAN NOPTI\n CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)\n RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)\n RAX: 00000000ffffffff\n Call Trace:\n  \u003cTASK\u003e\n  bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)\n  bpf_core_apply (kernel/bpf/btf.c:9507)\n  check_core_relo (kernel/bpf/verifier.c:19475)\n  bpf_check (kernel/bpf/verifier.c:26031)\n  bpf_prog_load (kernel/bpf/syscall.c:3089)\n  __sys_bpf (kernel/bpf/syscall.c:6228)\n  \u003c/TASK\u003e\n\nCO-RE accessor indices are inherently non-negative (struct member index,\narray element index, or enumerator index), so reject them immediately\nafter parsing.",
  "id": "CVE-2026-45839",
  "modified": "2026-07-15T01:49:06.292376589Z",
  "published": "2026-05-27T09:24:37.855Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1c22483a2c4bbf747787f328392ca3e68619c4dc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3ff85ae79e1a74baeb916b78a63d821f6d19a994"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/669349b4612c26b3d7aacfa99d7174681bd19223"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/76f2ebaf79a9ae6d0737b87f045fe769e425d78f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/99dbab7b5a12d8f58d5b0aa2f7a1fe656a70f4b2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a9e777f856cd2f1efc106afc7bf21aef868509d5"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45839.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45839"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "bpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()"
}