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

CVE-2026-98405: smb: client: fix missing iov bounds check in parse_posix_sids()

Noroxi assessment

Priority: Monitor (action score 32/100)

  • 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: 0.47% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2f8ed71aaaba3bc8b19cd9930cc62e63e142b299, 6.6.158, b09d092eb24ad0110f16a9b7c1ed5d2a0c1733dc; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2f8ed71aaaba3bc8b19cd9930cc62e63e142b299, 6.6.158, b09d092eb24ad0110f16a9b7c1ed5d2a0c1733dc; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1 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: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats the bounds guards in posix_info_sid_size(), allowing out-of-bounds reads into adjacent kernel memory. Fix this by rejecting responses where the calculated sidsbuf_end would exceed the received iov boundaries or cause pointer wraparound.

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Oct 14, 2026
Updated
Oct 24, 2026
EPSS
0.4% · 41th percentile
CWE
—

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CNA vs NVD score

NVD
—
CNA · Linux
8.1
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.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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

Follow CVE-2026-98405

When you'll hear from us

  • when it enters CISA KEV
  • 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.

—

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

    • 6.8affected
    • a90f37e3d7acfd9824f162830583bbf7846fe252 and later · before d91b9a3b2b38e5ac1b51e9e5b23fe53ad7b49644affected · git
    • 858e74876c5cbff1dfd5bace99e32fbce2abd4b5 and later · before b862996e5105be1293da9cdc85da77b76021c3bdaffected · git
    • 858e74876c5cbff1dfd5bace99e32fbce2abd4b5 and later · before 2f8ed71aaaba3bc8b19cd9930cc62e63e142b299affected · git
    • 858e74876c5cbff1dfd5bace99e32fbce2abd4b5 and later · before eac6917a42899aad0617bbf04798c5dd946a1fe5affected · git
    • 858e74876c5cbff1dfd5bace99e32fbce2abd4b5 and later · before b09d092eb24ad0110f16a9b7c1ed5d2a0c1733dcaffected · git
    • 6.6.32 and later · before 6.6.158affected · semver
    • before 6.8not affected · semver
    • 6.6.158 and later · up to and including 6.6.*not affected · semver
    • 6.12.112 and later · up to and including 6.12.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
openSUSE:Tumbleweedkernel-sourcebefore 7.2.11-1.17.2.11-1.1

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-2026-98403Oct 14, 2026 · s390/boot: Avoid IPL parameter append past command line
    0Monitor
  • ← EarlierCVE-2026-98404Oct 14, 2026 · drm/virtio: Fix a NULL vs ERR_PTR() bug in virtio_gpu_user_framebuffer_create()
    0Monitor
  • Later →CVE-2026-98406Oct 14, 2026 · wifi: mac80211: avoid WARN in set_bitrate_mask when sdata not in driver
    0Monitor

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 Linux2f8ed71aaaba3bc8b19cd9930cc62e63e142b299Vendor (CNA)
Linux Linux6.6.158Vendor (CNA)
Linux Linuxb09d092eb24ad0110f16a9b7c1ed5d2a0c1733dcVendor (CNA)
Linux Linuxb862996e5105be1293da9cdc85da77b76021c3bdVendor (CNA)
Linux Linuxd91b9a3b2b38e5ac1b51e9e5b23fe53ad7b49644Vendor (CNA)
Linux Linuxeac6917a42899aad0617bbf04798c5dd946a1fe5Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.159.1-1 · Release NotesMicrosoft (MSRC)
opensuse:kernel-source7.2.11-1.1 · openSUSE:TumbleweedPackage 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+22 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

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

—

CVSS vector

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

Change log

  1. CVSS— → 8.1
  2. Severity— → high
  3. Exploit maturity— → none
  4. Fix✗ → ✓

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

References

Show all references (4 more)

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

All records