{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "3f364222d032eea6b245780e845ad213dab28cdd"
            },
            {
              "fixed": "ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e"
            },
            {
              "fixed": "ddc34a1b85505c919026ddc82fafdada9a160b15"
            },
            {
              "fixed": "0db169a91381a473b7974021d1c02f8da72c5775"
            },
            {
              "fixed": "d7b87adeb0eb539b9b824b101bb14fb01e41240b"
            },
            {
              "fixed": "57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52"
            },
            {
              "fixed": "6557f1565d779851c4db9c488c49c05a47a6e72f"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.18.0"
            },
            {
              "fixed": "6.1.165"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.128"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.75"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.14"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45886.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix bpf_xdp_store_bytes proto for read-only arg\n\nWhile making some maps in Cilium read-only from the BPF side, we noticed\nthat the bpf_xdp_store_bytes proto is incorrect. In particular, the\nverifier was throwing the following error:\n\n  ; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr),\n                          \u0026nat-\u003eaddress, 4, 0);\n  635: (79) r1 = *(u64 *)(r10 -144)     ; R1=ctx() R10=fp0 fp-144=ctx()\n  636: (b4) w2 = 26                     ; R2=26\n  637: (b4) w4 = 4                      ; R4=4\n  638: (b4) w5 = 0                      ; R5=0\n  639: (85) call bpf_xdp_store_bytes#190\n  write into map forbidden, value_size=6 off=0 size=4\n\nnat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE.\nThe verifier checks the helper's memory access to R3 in\ncheck_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third\nargument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the\nMEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3.\nGiven R3 points to a read-only map, the check fails.\n\nConversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading\nfrom uninitialized memory.\n\nThis patch simply fixes the expected argument type to match that of\nbpf_skb_store_bytes.",
  "id": "CVE-2026-45886",
  "modified": "2026-07-08T05:38:22.779951185Z",
  "published": "2026-05-27T12:16:58Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d7b87adeb0eb539b9b824b101bb14fb01e41240b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45886.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45886"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "bpf: Fix bpf_xdp_store_bytes proto for read-only arg"
}