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

CVE-2026-98454: smb: client: fix create context out-of-bounds reads

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: 0.38% (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 05a7fd80024ff32b9b40ab1478bb172eeab1c386, 0a8c2a6715c2a67b7abbbf874fccc9f5518146d9, 28bc9a871799363afa3139e961a8e3684feb8704; 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 05a7fd80024ff32b9b40ab1478bb172eeab1c386, 0a8c2a6715c2a67b7abbbf874fccc9f5518146d9, 28bc9a871799363afa3139e961a8e3684feb8704; 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 create context out-of-bounds reads smb2_parse_contexts() validates the complete create-context area but does not limit each record to its Next field before dispatching it. A malformed chain can therefore expose bytes beyond the current context to a handler. The QFid handler also used a full response-structure cast although it only reads DiskFileId. The SMB2/SMB3 lease parsers made the same layout assumption: they read LeaseState and LeaseFlags at canonical offsets rather than at DataOffset. A valid non-canonical DataOffset could therefore yield unrelated in-bounds data, while a short DataLength was still accepted. Limit each context to its Next value, reject offsets before the context header, and reject malformed chains. Bound the name range by the current context and do not dispatch a known handler when DataLength is zero. Read the QFid DiskFileId only when the context data covers that field. Parse the lease context from DataOffset and require DataLength to match the v1 or v2 lease_context size used by ksmbd. A size mismatch skips lease parsing without failing the open.

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Oct 18, 2026
Updated
Oct 30, 2026
EPSS
0.3% · 33th 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 · 0.3%

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

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When you'll hear from us

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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

    • 3.7affected
    • b8c32dbb0deb287a5fcb78251e4eae6c7275760d and later · before 34245048d6c1fa6d7be4f0dec1d14b5be02360e1affected · git
    • b8c32dbb0deb287a5fcb78251e4eae6c7275760d and later · before 0a8c2a6715c2a67b7abbbf874fccc9f5518146d9affected · git
    • b8c32dbb0deb287a5fcb78251e4eae6c7275760d and later · before 43d0ca48bb902d554b6531862248810d2ae3b8efaffected · git
    • b8c32dbb0deb287a5fcb78251e4eae6c7275760d and later · before e4c49012708c917eafd9c27054b02d0f8b30fe64affected · git
    • b8c32dbb0deb287a5fcb78251e4eae6c7275760d and later · before 28bc9a871799363afa3139e961a8e3684feb8704affected · git
    • b8c32dbb0deb287a5fcb78251e4eae6c7275760d and later · before 05a7fd80024ff32b9b40ab1478bb172eeab1c386affected · git
    • b8c32dbb0deb287a5fcb78251e4eae6c7275760d and later · before cecc5399987e73a528ce2b662eeb54af69163cbdaffected · git
    • b8c32dbb0deb287a5fcb78251e4eae6c7275760d and later · before 67f4c1c6a1b51e203d986779299824d1c2c590a6affected · git
    • before 3.7not 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:12linux-6.12before 6.12.113-1~deb12u16.12.113-1~deb12u1
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.9-17.2.9-1

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-2026-98452Oct 18, 2026 · smb: client: clean up failed cached directory opens
    0Monitor
  • ← EarlierCVE-2026-98453Oct 18, 2026 · smb: client: close handle after create-context parsing failure
    0Monitor
  • Later →CVE-2026-98455Oct 18, 2026 · Bluetooth: RFCOMM: fix NULL dereference of dlc->session in RFCOMM_CONNINFO
    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 Linux05a7fd80024ff32b9b40ab1478bb172eeab1c386Vendor (CNA)
Linux Linux0a8c2a6715c2a67b7abbbf874fccc9f5518146d9Vendor (CNA)
Linux Linux28bc9a871799363afa3139e961a8e3684feb8704Vendor (CNA)
Linux Linux34245048d6c1fa6d7be4f0dec1d14b5be02360e1Vendor (CNA)
Linux Linux43d0ca48bb902d554b6531862248810d2ae3b8efVendor (CNA)
Linux Linux67f4c1c6a1b51e203d986779299824d1c2c590a6Vendor (CNA)
Linux Linuxcecc5399987e73a528ce2b662eeb54af69163cbdVendor (CNA)
Linux Linuxe4c49012708c917eafd9c27054b02d0f8b30fe64Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.159.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.113-1~deb12u1 · Debian:12Package 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 11, 2026+24 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 (7 more)

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

All records