CVE-2026-98403

Status: ReceivedUnscored—

Severity—Unscored

Exploitation probability0.21 %higher than 11% of CVEs

Active exploitationNonot in the CISA catalog

Public exploitNot knownno public code found

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

s390/boot: Avoid IPL parameter append past command line

A command line may occupy all but the terminating byte of COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size to the IPL parameter conversion helpers and points the destination one byte past early_command_line. The helpers subtract one from the unsigned size and write the converted parameter outside the command line buffer.

Convert the IPL parameter in the command line parsing buffer first. A parameter beginning with '=' can then replace the existing command line regardless of its length, while other parameters are appended only when space remains.

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: 11
Score date: 10/21/2026

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 4 references

Raw JSON (NVD)

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{
  "id": "CVE-2026-98403",
  "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": "5ecb2da660ab8eddafe059a6a8a708465db89ca2",
              "lessThan": "af9866021a00ab9eeacf0c33ee73f3d134b4ed70",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "5ecb2da660ab8eddafe059a6a8a708465db89ca2",
              "lessThan": "73eec5a0d55916d7e1115f5d03a7ffc06d6215cf",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "5ecb2da660ab8eddafe059a6a8a708465db89ca2",
              "lessThan": "8d11bfec8666f8409fac9072e9c25b691d3e30ac",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "5ecb2da660ab8eddafe059a6a8a708465db89ca2",
              "lessThan": "d76181dfabdaa720703167393704efacba343442",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "arch/s390/boot/ipl_parm.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.16"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.16",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "arch/s390/boot/ipl_parm.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-10-14T14:17:51.383",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/73eec5a0d55916d7e1115f5d03a7ffc06d6215cf",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8d11bfec8666f8409fac9072e9c25b691d3e30ac",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/af9866021a00ab9eeacf0c33ee73f3d134b4ed70",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d76181dfabdaa720703167393704efacba343442",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/boot: Avoid IPL parameter append past command line\n\nA command line may occupy all but the terminating byte of\nCOMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size\nto the IPL parameter conversion helpers and points the destination one\nbyte past early_command_line. The helpers subtract one from the unsigned\nsize and write the converted parameter outside the command line buffer.\n\nConvert the IPL parameter in the command line parsing buffer first. A\nparameter beginning with '=' can then replace the existing command line\nregardless of its length, while other parameters are appended only when\nspace remains."
    }
  ],
  "lastModified": "2026-10-19T10:18:45.243",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}