{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "ae98dbf43d755b4e111fcd086e53939bef3e9a1a"
            },
            {
              "fixed": "f40570fda3f3a1f96aeaa4aef665ba274b2810b5"
            },
            {
              "fixed": "0bbc9481f970b0b4ddb08cfa464db1cc93b74b56"
            },
            {
              "fixed": "4973232a67e4137ab9399f504f7f2bdd847f96d2"
            },
            {
              "fixed": "ed46f39c47eb5530a9c161481a2080d3a869cfaf"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.12.0"
            },
            {
              "fixed": "6.12.94"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.36"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53191.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retries\n\nWhen a bundle recv retries inside io_recv_finish(), the merge logic OR\nthe saved cflags from the previous iteration with the cflags returned by\nthe new iteration:\n  cflags = req-\u003ecqe.flags | (cflags \u0026 CQE_F_MASK);\n\nBits listed in CQE_F_MASK are inherited from the new iteration, and all\nother bits (notably IORING_CQE_F_BUFFER and the buffer ID) come from the\nsaved cflags. Before this change CQE_F_MASK covered only\nIORING_CQE_F_SOCK_NONEMPTY and IORING_CQE_F_MORE.\n\nWhen using provided buffer rings (IOU_PBUF_RING_INC) with incremental\nmode, and bundle recv, io_kbuf_inc_commit() can leave the head ring\nentry partially consumed, __io_put_kbufs() then sets\nIORING_CQE_F_BUF_MORE on the returned cflags so userspace knows the\nbuffer ID will be reused for subsequent completions.\n\nBecause IORING_CQE_F_BUF_MORE was not in CQE_F_MASK, the merge above\nsilently dropped it whenever the final retry iteration partially\nconsumed the buffer, and the subsequent req-\u003ecqe.flags = cflags \u0026\n~CQE_F_MASK save would have left a stale IORING_CQE_F_BUF_MORE in the\ncarried-over cflags had one been present. Userspace would then\nwrongfully advance it ring head past an entry the kernel still uses.\n\nAdd IORING_CQE_F_BUF_MORE to CQE_F_MASK so it is both inherited from the\nnew iteration into the user-visible CQE and stripped from the saved\ncflags between iterations.",
  "id": "CVE-2026-53191",
  "modified": "2026-07-08T05:37:03.569420970Z",
  "published": "2026-06-25T08:39:03.052Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0bbc9481f970b0b4ddb08cfa464db1cc93b74b56"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4973232a67e4137ab9399f504f7f2bdd847f96d2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ed46f39c47eb5530a9c161481a2080d3a869cfaf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f40570fda3f3a1f96aeaa4aef665ba274b2810b5"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53191.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53191"
    },
    {
      "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": "io_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retries"
}