Vulnerability-Lookup

FKIE_CVE-2026-31432

Vulnerability from fkie_nvd - Published: 2026-04-22 09:16 - Updated: 2026-05-21 17:28

Severity

8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix OOB write in QUERY_INFO for compound requests When a compound request such as READ + QUERY_INFO(Security) is received, and the first command (READ) consumes most of the response buffer, ksmbd could write beyond the allocated buffer while building a security descriptor. The root cause was that smb2_get_info_sec() checked buffer space using ppntsd_size from xattr, while build_sec_desc() often synthesized a significantly larger descriptor from POSIX ACLs. This patch introduces smb_acl_sec_desc_scratch_len() to accurately compute the final descriptor size beforehand, performs proper buffer checking with smb2_calc_max_out_buf_len(), and uses exact-sized allocation + iov pinning.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/075ea208c648cc2bcd616295b711d3637c61de45	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/515c2daab46021221bdf406bef19bc90a44ec617	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d48c64fb80ad78b3dd29fb7d79b6ec7bd72bfc09	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/fda9522ed6afaec45cabc198d8492270c394c7bc	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix OOB write in QUERY_INFO for compound requests\n\nWhen a compound request such as READ + QUERY_INFO(Security) is received,\nand the first command (READ) consumes most of the response buffer,\nksmbd could write beyond the allocated buffer while building a security\ndescriptor.\n\nThe root cause was that smb2_get_info_sec() checked buffer space using\nppntsd_size from xattr, while build_sec_desc() often synthesized a\nsignificantly larger descriptor from POSIX ACLs.\n\nThis patch introduces smb_acl_sec_desc_scratch_len() to accurately\ncompute the final descriptor size beforehand, performs proper buffer\nchecking with smb2_calc_max_out_buf_len(), and uses exact-sized\nallocation + iov pinning."
    }
  ],
  "id": "CVE-2026-31432",
  "lastModified": "2026-05-21T17:28:57.847",
  "metrics": {
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        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
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        "type": "Secondary"
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  "vulnStatus": "Analyzed",
  "weaknesses": [
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      "description": [
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          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-31432 (GCVE-0-2026-31432)

Vulnerability from cvelistv5 – Published: 2026-04-22 08:15 – Updated: 2026-05-23 16:04

Title

ksmbd: fix OOB write in QUERY_INFO for compound requests

Summary

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/d48c64fb80ad78b3d…
https://git.kernel.org/stable/c/075ea208c648cc2bc…
https://git.kernel.org/stable/c/515c2daab46021221…
https://git.kernel.org/stable/c/fda9522ed6afaec45…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < d48c64fb80ad78b3dd29fb7d79b6ec7bd72bfc09 (git) Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < 075ea208c648cc2bcd616295b711d3637c61de45 (git) Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < 515c2daab46021221bdf406bef19bc90a44ec617 (git) Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < fda9522ed6afaec45cabc198d8492270c394c7bc (git) Affected: f2283680a80571ca82d710bc6ecd8f8beac67d63 (git) Affected: 9f297df20d93411c0b4ddad7f88ba04a7cd36e77 (git) Affected: 5.15.145 , < 5.16 (semver) Affected: 6.1.71 , < 6.2 (semver)
Linux	Linux	Affected: 6.6 Unaffected: 0 , < 6.6 (semver) Unaffected: 6.12.81 , ≤ 6.12.* (semver) Unaffected: 6.18.22 , ≤ 6.18.* (semver) Unaffected: 6.19.12 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

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        {
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          "programFiles": [
            "fs/smb/server/smb2pdu.c",
            "fs/smb/server/smbacl.c",
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          ],
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2026-31432

CVE-2026-31432 (GCVE-0-2026-31432)

Tags

Sightings

Nomenclature