CVE-2026-31708

HIGHPre-NVD 8.18.1
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-05-01. the CNA's CVSS baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

A fix is available — apply it.

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

smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path

smb2_ioctl_query_info() has two response-copy branches: PASSTHRU_FSCTL and the default QUERY_INFO path. The QUERY_INFO branch clamps qi.input_buffer_length to the server-reported OutputBufferLength and then copies qi.input_buffer_length bytes from qi_rsp->Buffer to userspace, but it never verifies that the flexible-array payload actually fits within rsp_iov[1].iov_len.

A malicious server can return OutputBufferLength larger than the actual QUERY_INFO response, causing copy_to_user() to walk past the response buffer and expose adjacent kernel heap to userspace.

Guard the QUERY_INFO copy with a bounds check on the actual Buffer payload. Use struct_size(qi_rsp, Buffer, qi.input_buffer_length) rather than an open-coded addition so the guard cannot overflow on 32-bit builds.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

Published

May 1, 2026

Last Modified

August 5, 2026

Advisory Details (5)

Auto-updated May 3, 2026
No patch confirmed yet.
generic

smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ac2f14e4705d020f04e806efa0d49ab8dc2b145f
generic

smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a58c5af19ff0d6f44f6e9fe31e33a2c92223f77e
generic

smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a34d456934fe42e4da5d2cc07787bf418bee99c6
generic

smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/85fd46ee26a11841c670449508025965f61ce131
generic

smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/078fae8f50adebb903ccf2252b44391324571e78

Vendor Advisories for CVE-2026-31708(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(19)

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)5.10.259-1
linux-6.16.1.106-3~deb11u1 ... 6.1.174-1~deb11u1 (20 versions)6.1.176-1~deb11u1
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)6.1.176-1
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)6.12.85-1
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.1-1~exp1 (129 versions)7.0.3-1

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(18)

Data Freshness Timeline

(refreshed 8× in last 7d / 67× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 251 total refreshes for this CVE.

  1. 2026-09-04 05:06 UTCEPSS rescore
  2. 2026-09-04 00:59 UTCOSV refresh
  3. 2026-09-02 14:11 UTCEPSS rescore
  4. 2026-09-01 13:53 UTCEPSS rescore
  5. 2026-09-01 04:39 UTCEPSS rescore
  6. 2026-09-01 04:39 UTCEPSS rescore
  7. 2026-08-30 19:17 UTCEPSS rescore
  8. 2026-08-30 01:22 UTCEPSS rescore
  9. 2026-08-28 21:41 UTCEPSS rescore
  10. 2026-08-27 14:25 UTCEPSS rescore
  11. 2026-08-26 14:46 UTCEPSS rescore
  12. 2026-08-25 13:49 UTCEPSS rescore
  13. 2026-08-24 14:17 UTCEPSS rescore
  14. 2026-08-23 00:19 UTCEPSS rescore
  15. 2026-08-21 23:49 UTCEPSS rescore
  16. 2026-08-20 22:55 UTCEPSS rescore
  17. 2026-08-20 22:55 UTCEPSS rescore
  18. 2026-08-19 17:03 UTCEPSS rescore
  19. 2026-08-18 13:48 UTCEPSS rescore
  20. 2026-08-17 13:47 UTCEPSS rescore
  21. 2026-08-17 13:45 UTCEG score recompute
  22. 2026-08-17 13:45 UTCVendor advisory
  23. 2026-08-17 13:45 UTCGHSA enrichment
  24. 2026-08-16 14:56 UTCEPSS rescore
  25. 2026-08-16 05:19 UTCEG score recompute
Show 75 more
  1. 2026-08-16 05:19 UTCVendor advisory
  2. 2026-08-16 05:19 UTCGHSA enrichment
  3. 2026-08-16 02:14 UTCEPSS rescore
  4. 2026-08-15 01:30 UTCEPSS rescore
  5. 2026-08-14 16:59 UTCVendor advisory
  6. 2026-08-14 16:59 UTCGHSA enrichment
  7. 2026-08-14 03:47 UTCEG score recompute
  8. 2026-08-14 03:47 UTCVendor advisory
  9. 2026-08-14 03:47 UTCGHSA enrichment
  10. 2026-08-13 22:00 UTCEPSS rescore
  11. 2026-08-13 06:42 UTCVendor advisory
  12. 2026-08-13 06:42 UTCGHSA enrichment
  13. 2026-08-12 17:25 UTCEG score recompute
  14. 2026-08-12 17:25 UTCVendor advisory
  15. 2026-08-12 17:25 UTCGHSA enrichment
  16. 2026-08-12 13:50 UTCEPSS rescore
  17. 2026-08-11 16:22 UTCEG score recompute
  18. 2026-08-11 16:22 UTCVendor advisory
  19. 2026-08-11 16:22 UTCGHSA enrichment
  20. 2026-08-11 01:49 UTCEG score recompute
  21. 2026-08-11 01:49 UTCVendor advisory
  22. 2026-08-11 01:49 UTCGHSA enrichment
  23. 2026-08-11 00:00 UTCEPSS rescore
  24. 2026-08-10 05:12 UTCVendor advisory
  25. 2026-08-10 05:12 UTCGHSA enrichment
  26. 2026-08-09 16:05 UTCEG score recompute
  27. 2026-08-09 16:05 UTCVendor advisory
  28. 2026-08-09 16:05 UTCGHSA enrichment
  29. 2026-08-09 13:46 UTCEPSS rescore
  30. 2026-08-09 02:57 UTCEG score recompute
  31. 2026-08-09 02:57 UTCVendor advisory
  32. 2026-08-09 02:57 UTCGHSA enrichment
  33. 2026-08-08 16:37 UTCEPSS rescore
  34. 2026-08-08 01:26 UTCEG score recompute
  35. 2026-08-08 01:26 UTCVendor advisory
  36. 2026-08-08 01:26 UTCGHSA enrichment
  37. 2026-08-07 12:19 UTCVendor advisory
  38. 2026-08-07 12:19 UTCGHSA enrichment
  39. 2026-08-06 17:06 UTCEG score recompute
  40. 2026-08-06 17:06 UTCVendor advisory
  41. 2026-08-06 17:06 UTCGHSA enrichment
  42. 2026-08-06 13:46 UTCEPSS rescore
  43. 2026-08-06 01:43 UTCEG score recompute
  44. 2026-08-06 01:43 UTCVendor advisory
  45. 2026-08-06 01:43 UTCGHSA enrichment
  46. 2026-08-05 19:17 UTCEPSS rescore
  47. 2026-08-05 12:36 UTCEG score recompute
  48. 2026-08-05 12:36 UTCVendor advisory
  49. 2026-08-05 12:36 UTCGHSA enrichment
  50. 2026-08-04 15:10 UTCEPSS rescore
  51. 2026-08-04 10:38 UTCEPSS rescore
  52. 2026-08-03 20:25 UTCEG score recompute
  53. 2026-08-03 20:25 UTCVendor advisory
  54. 2026-08-03 20:25 UTCGHSA enrichment
  55. 2026-08-03 10:36 UTCEPSS rescore
  56. 2026-08-02 18:49 UTCVendor advisory
  57. 2026-08-02 18:49 UTCGHSA enrichment
  58. 2026-08-02 05:41 UTCEG score recompute
  59. 2026-08-02 05:41 UTCVendor advisory
  60. 2026-08-02 05:41 UTCGHSA enrichment
  61. 2026-08-02 02:27 UTCEPSS rescore
  62. 2026-08-01 04:16 UTCEPSS rescore
  63. 2026-07-30 16:28 UTCEPSS rescore
  64. 2026-07-30 01:30 UTCEPSS rescore
  65. 2026-07-28 15:36 UTCEPSS rescore
  66. 2026-07-26 14:54 UTCEPSS rescore
  67. 2026-07-26 14:54 UTCEPSS rescore
  68. 2026-07-25 14:18 UTCEPSS rescore
  69. 2026-07-25 14:17 UTCEPSS rescore
  70. 2026-07-24 14:17 UTCEPSS rescore
  71. 2026-07-23 14:18 UTCEPSS rescore
  72. 2026-07-23 14:18 UTCEPSS rescore
  73. 2026-07-23 03:08 UTCEG score recompute
  74. 2026-07-22 14:08 UTCEPSS rescore
  75. 2026-07-22 14:08 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-31708?
CVE-2026-31708 is a high vulnerability published on May 1, 2026. In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB read in smb2ioctlqueryinfo QUERYINFO path smb2ioctlqueryinfo() has two response-copy branches: PASSTHRUFSCTL and the default QUERYINFO path. The QUERYINFO branch clamps qi.inputbufferlength to the…
When was CVE-2026-31708 disclosed?
CVE-2026-31708 was first published in the National Vulnerability Database on May 1, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-31708 actively exploited?
CVE-2026-31708 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 77.0% of all scored CVEs.
What is the CVSS score of CVE-2026-31708?
CVE-2026-31708 has a CVSS v4.0 base score of 8.1 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-31708?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31708, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-31708

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