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NVD / CVE Program· CNA Linux

CVE-2026-31717: ksmbd: validate owner of durable handle on reconnect

HighCVSS 8.8 · v3.1—Proof of concept Fix available

Noroxi assessment

Priority: Monitor (action score 35/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.43% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 00ce8d6789dae72d042a4522264964c72891ca37, 49110a8ce654bbe56bef7c5e44cce31f4b102b8a, 6.6.142.

Low priority for now. Upgrade to Linux Linux 00ce8d6789dae72d042a4522264964c72891ca37, 49110a8ce654bbe56bef7c5e44cce31f4b102b8a, 6.6.142 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate owner of durable handle on reconnect Currently, ksmbd does not verify if the user attempting to reconnect to a durable handle is the same user who originally opened the file. This allows any authenticated user to hijack an orphaned durable handle by predicting or brute-forcing the persistent ID. According to MS-SMB2, the server MUST verify that the SecurityContext of the reconnect request matches the SecurityContext associated with the existing open. Add a durable_owner structure to ksmbd_file to store the original opener's UID, GID, and account name. and catpure the owner information when a file handle becomes orphaned. and implementing ksmbd_vfs_compare_durable_owner() to validate the identity of the requester during SMB2_CREATE (DHnC).

Published
May 1, 2026
Updated
Nov 11, 2026
EPSS
0.4% · 38th percentile
CWE
—

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CNA vs NVD score

NVD
—
CNA · Linux
8.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-31717

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.9affected
    • 8df4bcdb0a4232192b2445256c39b787d58ef14d and later · before 712cdf917e77a6444ce3836874829d770db20ee6affected · git
    • c8efcc786146a951091588e5fa7e3c754850cb3c and later · before c7f0f0d01c88bdcb8b1694d7d321670013f7ed7daffected · git
    • c8efcc786146a951091588e5fa7e3c754850cb3c and later · before 00ce8d6789dae72d042a4522264964c72891ca37affected · git
    • c8efcc786146a951091588e5fa7e3c754850cb3c and later · before c908c853f304a4969b5aa10eba0b50350cc65b80affected · git
    • c8efcc786146a951091588e5fa7e3c754850cb3c and later · before 49110a8ce654bbe56bef7c5e44cce31f4b102b8aaffected · git
    • 6.6.32 and later · before 6.6.142affected · semver
    • before 6.9not affected · semver
    • 6.6.142 and later · up to and including 6.6.*not affected · semver
    • 6.12.92 and later · up to and including 6.12.*not affected · semver
Affected versions · NVD (4)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.6.32 and later · before 6.7
  • linux linux kernel6.9 and later · before 6.18.25
  • linux linux kernel6.19 and later · before 7.0.2
  • linux linux kernel7.1

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.3-17.0.3-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-31715May 1, 2026 · f2fs: fix UAF caused by decrementing sbi->nr_pages[] in f2fs_write_end_io()
    31Monitor
  • ← EarlierCVE-2026-31716May 1, 2026 · fs/ntfs3: validate rec->used in journal-replay file record check
    31Monitor
  • Later →CVE-2026-31718May 1, 2026 · ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger
    39Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux00ce8d6789dae72d042a4522264964c72891ca37Vendor (CNA)
Linux Linux49110a8ce654bbe56bef7c5e44cce31f4b102b8aVendor (CNA)
Linux Linux6.6.142Vendor (CNA)
Linux Linux712cdf917e77a6444ce3836874829d770db20ee6Vendor (CNA)
Linux Linuxc7f0f0d01c88bdcb8b1694d7d321670013f7ed7dVendor (CNA)
Linux Linuxc908c853f304a4969b5aa10eba0b50350cc65b80Vendor (CNA)
debian:linux6.12.94-1 · Debian:13Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:52026-05-04

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+2 d
  3. TodayNov 13, 2026+196 d

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records