{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "4c03342e5ac532fb34d13a7b51dd7261dfc48963"
            },
            {
              "fixed": "a17443af874229408ce6b78e2c8a2b5adeb4b7d8"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "d00ce96623a69a100ad79675d0e85fda3c50d89b"
            },
            {
              "fixed": "0d15c3611a2cc5d08993545d4032055ae10ae2c1"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "9d21199842247ab05c675fb9b6c6ca393a5c0024"
            },
            {
              "fixed": "a3125bc01884431d30d731461634c8295b6f0529"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.18.17"
            },
            {
              "fixed": "6.18.21"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.7"
            },
            {
              "fixed": "6.19.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43070.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reset register ID for BPF_END value tracking\n\nWhen a register undergoes a BPF_END (byte swap) operation, its scalar\nvalue is mutated in-place. If this register previously shared a scalar ID\nwith another register (e.g., after an `r1 = r0` assignment), this tie must\nbe broken.\n\nCurrently, the verifier misses resetting `dst_reg-\u003eid` to 0 for BPF_END.\nConsequently, if a conditional jump checks the swapped register, the\nverifier incorrectly propagates the learned bounds to the linked register,\nleading to false confidence in the linked register's value and potentially\nallowing out-of-bounds memory accesses.\n\nFix this by explicitly resetting `dst_reg-\u003eid` to 0 in the BPF_END case\nto break the scalar tie, similar to how BPF_NEG handles it via\n`__mark_reg_known`.",
  "id": "CVE-2026-43070",
  "modified": "2026-07-08T05:36:49.601947567Z",
  "published": "2026-05-05T15:23:28.819Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0d15c3611a2cc5d08993545d4032055ae10ae2c1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a17443af874229408ce6b78e2c8a2b5adeb4b7d8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a3125bc01884431d30d731461634c8295b6f0529"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43070.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43070"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "bpf: Reset register ID for BPF_END value tracking"
}