CVE-2026-99096 (GCVE-0-2026-99096)

Vulnerability from cvelistv5 – Published: 2026-10-26 14:52 – Updated: 2026-10-26 14:52
VLAI
Title
io_uring/register: don't exempt disabled rings from task restrictions
Summary
In the Linux kernel, the following vulnerability has been resolved: io_uring/register: don't exempt disabled rings from task restrictions A ring created with IORING_SETUP_R_DISABLED is exempt from its register restrictions until it is enabled. This lets the creator register the restrictions and then enable the ring with IORING_REGISTER_ENABLE_RINGS, whether or not that opcode is in the allowed set. Since commit ed82f35b926b ("io_uring: allow registration of per-task restrictions"), a ring also inherits restrictions from the task that creates it, and the same exemption applies to those. A task whose register opcodes are restricted can therefore create a disabled ring, issue any register opcode on it, and then enable it. Mark rings whose restrictions were inherited from the task, and keep checking register opcodes for them while the ring is disabled. Enabling such a ring now requires IORING_REGISTER_ENABLE_RINGS to be in the task's allowed set. Per-ring restrictions registered on a disabled ring work as before. [axboe: amend with inheritance flag fixup]
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 7033 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: ed82f35b926b2e505c14b7006473614b8f58b4f4 , < f55c240192ded562386de843bfa067671d2731d5 (git)
Affected: ed82f35b926b2e505c14b7006473614b8f58b4f4 , < 6da8f402e362b2f546e2efb7167fc9597aef6faf (git)
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Linux Linux Affected: 7.0
Unaffected: 0 , < 7.0 (semver)
Unaffected: 7.2.11 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
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Show details on NVD website
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{
  "containers": {
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          "product": "Linux",
          "programFiles": [
            "include/linux/io_uring_types.h",
            "io_uring/io_uring.c",
            "io_uring/register.c"
          ],
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          "versions": [
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            }
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              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/register: don\u0027t exempt disabled rings from task restrictions\n\nA ring created with IORING_SETUP_R_DISABLED is exempt from its register\nrestrictions until it is enabled. This lets the creator register the\nrestrictions and then enable the ring with IORING_REGISTER_ENABLE_RINGS,\nwhether or not that opcode is in the allowed set.\n\nSince commit ed82f35b926b (\"io_uring: allow registration of per-task\nrestrictions\"), a ring also inherits restrictions from the task that\ncreates it, and the same exemption applies to those. A task whose\nregister opcodes are restricted can therefore create a disabled ring,\nissue any register opcode on it, and then enable it.\n\nMark rings whose restrictions were inherited from the task, and keep\nchecking register opcodes for them while the ring is disabled. Enabling\nsuch a ring now requires IORING_REGISTER_ENABLE_RINGS to be in the\ntask\u0027s allowed set. Per-ring restrictions registered on a disabled ring\nwork as before.\n\n[axboe: amend with inheritance flag fixup]"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-26T14:52:03.236Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f55c240192ded562386de843bfa067671d2731d5"
        },
        {
          "url": "https://git.kernel.org/stable/c/6da8f402e362b2f546e2efb7167fc9597aef6faf"
        }
      ],
      "title": "io_uring/register: don\u0027t exempt disabled rings from task restrictions",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-99096",
    "datePublished": "2026-10-26T14:52:03.236Z",
    "dateReserved": "2026-09-25T10:25:14.390Z",
    "dateUpdated": "2026-10-26T14:52:03.236Z",
    "state": "PUBLISHED"
  },
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  "vulnerability-lookup:meta": {
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      "date": "2026-10-28",
      "epss": "0.00152",
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                "product": "Linux",
                "programFiles": [
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                  "io_uring/io_uring.c",
                  "io_uring/register.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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                    "versionType": "git"
                  },
                  {
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                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
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                    "version": "0",
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                  }
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              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/register: don\u0027t exempt disabled rings from task restrictions\n\nA ring created with IORING_SETUP_R_DISABLED is exempt from its register\nrestrictions until it is enabled. This lets the creator register the\nrestrictions and then enable the ring with IORING_REGISTER_ENABLE_RINGS,\nwhether or not that opcode is in the allowed set.\n\nSince commit ed82f35b926b (\"io_uring: allow registration of per-task\nrestrictions\"), a ring also inherits restrictions from the task that\ncreates it, and the same exemption applies to those. A task whose\nregister opcodes are restricted can therefore create a disabled ring,\nissue any register opcode on it, and then enable it.\n\nMark rings whose restrictions were inherited from the task, and keep\nchecking register opcodes for them while the ring is disabled. Enabling\nsuch a ring now requires IORING_REGISTER_ENABLE_RINGS to be in the\ntask\u0027s allowed set. Per-ring restrictions registered on a disabled ring\nwork as before.\n\n[axboe: amend with inheritance flag fixup]"
          }
        ],
        "id": "CVE-2026-99096",
        "lastModified": "2026-10-26T15:16:48.633",
        "metrics": {},
        "published": "2026-10-26T15:16:48.633",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/6da8f402e362b2f546e2efb7167fc9597aef6faf"
          },
          {
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          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-10-29T07:19:54+00:00",
      "cve": "CVE-2026-99096",
      "id": "CVE-2026-99096",
      "initial_release_date": "2026-10-26T00:00:00+00:00",
      "product_status:known_affected": "49",
      "product_status:known_not_affected": "229",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: io_uring/register: don\u0027t exempt disabled rings from task restrictions",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-99096.json",
      "version": "3"
    }
  }
}



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