CVE-2026-98820

Status: ReceivedUnscored—

Severity—Unscored

Exploitation probability0.21 %higher than 10% of CVEs

Active exploitationNonot in the CISA catalog

Public exploitNot knownno public code found

In the Linux kernel, the following vulnerability has been resolved:

blk-mq: set RQF_USE_SCHED when the operation is known

The cached requests are allocated for one operation but can be handed out for another. A passthrough command has RQF_USE_SCHED cleared, so using those flags for a subsequent read/write bio will insert it into the scheduler without ->prepare_request() and frees it without ->finish_request(). For kyber, this leaks the domain token acquired at dispatch and stalls the queue.

Don't set RQF_USE_SCHED based on the first operation the batch happened to be allocated for. Instead, set it after the request is claimed by an operation. Introduce a helper function, blk_mq_rq_late_init() for this, and absorb blk_mq_rq_time_init() since the two run together.

CVSS

NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.21 %
Percentile among all scored CVEs: 10
Score date: 10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Linux — Linux Kernel^AI

References

Show 3 references

Raw JSON (NVD)

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{
  "id": "CVE-2026-98820",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4b6a5d9cea911424e84107df8c4eb8317938d2cd",
              "lessThan": "790730e4d95de8356a573d4b4864486bba731863",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4b6a5d9cea911424e84107df8c4eb8317938d2cd",
              "lessThan": "2c47ebc27fa72078e26177cd458cdaf3006a9685",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4b6a5d9cea911424e84107df8c4eb8317938d2cd",
              "lessThan": "ab6c756f28c741d704a7c3e04814bfc3adf6f818",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "block/blk-mq.c",
            "block/mq-deadline.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.1",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "block/blk-mq.c",
            "block/mq-deadline.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-10-18T16:17:36.240",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/2c47ebc27fa72078e26177cd458cdaf3006a9685",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/790730e4d95de8356a573d4b4864486bba731863",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ab6c756f28c741d704a7c3e04814bfc3adf6f818",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: set RQF_USE_SCHED when the operation is known\n\nThe cached requests are allocated for one operation but can be handed\nout for another. A passthrough command has RQF_USE_SCHED cleared, so\nusing those flags for a subsequent read/write bio will insert it into\nthe scheduler without ->prepare_request() and frees it without\n->finish_request(). For kyber, this leaks the domain token acquired at\ndispatch and stalls the queue.\n\nDon't set RQF_USE_SCHED based on the first operation the batch happened\nto be allocated for. Instead, set it after the request is claimed by an\noperation. Introduce a helper function, blk_mq_rq_late_init() for this,\nand absorb blk_mq_rq_time_init() since the two run together."
    }
  ],
  "lastModified": "2026-10-19T10:19:46.087",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}