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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-99115: ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 1d644ab9eac767d52c9b8dc0eb68c0085994d9b6, ab057f271ef60ff8163818badc3de75c480eca07, beba2ef6f66a71f20531ac70a1acb0b221e362e9; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1d644ab9eac767d52c9b8dc0eb68c0085994d9b6, ab057f271ef60ff8163818badc3de75c480eca07, beba2ef6f66a71f20531ac70a1acb0b221e362e9; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes 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: fill in FileSysIdentifier in FS_POSIX_INFORMATION smb2_get_info_filesystem() reports 56 bytes for FS_POSIX_INFORMATION, that is the whole of FILE_SYSTEM_POSIX_INFO, but never assigns FileSysIdentifier. Those eight bytes go to the client as they are found in the response buffer. The buffer is zeroed on allocation, so a standalone request leaks nothing. A compound request can leak: the offset of the next response is advanced by the length pinned for the previous one, so a reply that was written into the buffer and then dropped in favour of the short error response of smb2_set_err_rsp() stays there, and the next reply is laid over it with only the header cleared. Report the file system id statfs() returned, which is what the field is for. FileSysIdentifier is __le64 and f_fsid is a pair of ints, so assemble the value first, val[0] as the low half, and convert it on the way out.

—No exploit Fix available
Published
Oct 28, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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  • No public exploit code on record
  • A fix has been released

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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.

—

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

    • 5.15affected
    • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before cb9fbcaf1f3351bea771eec557fc6c4d2f35762baffected · git
    • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before 1d644ab9eac767d52c9b8dc0eb68c0085994d9b6affected · git
    • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before da2ec27fdd7effbe4c94ec15b6c6a281800c5123affected · git
    • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before f5c50f69a70fe22c44a50c869c8cd65fc35a0686affected · git
    • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before beba2ef6f66a71f20531ac70a1acb0b221e362e9affected · git
    • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before ab057f271ef60ff8163818badc3de75c480eca07affected · git
    • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before db2267b27c054a6c2151ff7fbb67927e784f31d6affected · git
    • before 5.15not affected · semver
    • 5.15.224 and later · up to and including 5.15.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.115-26.12.115-2

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-99113Oct 28, 2026 · ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
    0Monitor
  • ← EarlierCVE-2026-99114Oct 28, 2026 · ksmbd: initialize FileSystemControlFlags in FS_CONTROL_INFORMATION
    0Monitor
  • Later →CVE-2026-99116Oct 28, 2026 · net: psp: do not inherit the Rx association on clone
    31Monitor

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 Linux1d644ab9eac767d52c9b8dc0eb68c0085994d9b6Vendor (CNA)
Linux Linuxab057f271ef60ff8163818badc3de75c480eca07Vendor (CNA)
Linux Linuxbeba2ef6f66a71f20531ac70a1acb0b221e362e9Vendor (CNA)
Linux Linuxcb9fbcaf1f3351bea771eec557fc6c4d2f35762bVendor (CNA)
Linux Linuxda2ec27fdd7effbe4c94ec15b6c6a281800c5123Vendor (CNA)
Linux Linuxdb2267b27c054a6c2151ff7fbb67927e784f31d6Vendor (CNA)
Linux Linuxf5c50f69a70fe22c44a50c869c8cd65fc35a0686Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux6.12.115-2 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

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. Fix recordedsame day
  3. TodayNov 5, 2026+8 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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.

Change log

  1. Exploit maturity— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

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

All records