smb: client: fix create context out-of-bounds reads
Assessment
- Severity
- Moderate
- CVSS base score
- 6.3CVSS:3.1/
AV:N/ AC:L/ PR:N/ UI:R/ S:U/ C:L/ I:L/ A:L - Impact
- Not stated
- EPSS, next 30 days
- Not scored yet
- Public exploit code
- No Nuclei template lists it
- Exploitability
- Not assessed
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Mariner
- Weakness
- —
- Issued by
- Linux
- Published
- 20 Oct 2026 · October 2026
- Last revised
- 24 Oct 2026Information published.
- Attack vector
- NetworkAV:N
- Attack complexity
- LowAC:L
- Privileges required
- NonePR:N
- User interaction
- RequiredUI:R
- Scope
- UnchangedS:U
- Confidentiality
- LowC:L
- Integrity
- LowI:L
- Availability
- LowA:L
Updates that fix it
0 KBsNo KB listed
MSRC lists no downloadable update, which usually means a service-side fix or a release-notes update. Check the MSRC advisory.
Affected products
1 affected product
- azl3 kernel 6.6.157.1-1 on Azure Linux 3.0
What changed
First observed 20 Oct 2026- 25 Oct 2026 · 07:41:18 UTC Last revised21 Oct 2026 18:33 UTC → 24 Oct 2026 14:47 UTC
- 23 Oct 2026 · 09:33:49 UTC Public exploit codeUnknown: exploit-code evidence is incomplete or retained → No Nuclei template listed
- 23 Oct 2026 · 09:33:49 UTC CISA KEVUnknown: catalog evidence is incomplete or retained → Not listed in the collected catalog
- 23 Oct 2026 · 09:33:49 UTC Source coverage: public-exploit-codeIncomplete → Current
- 23 Oct 2026 · 09:33:49 UTC Source coverage: first-epssIncomplete → Current
- 23 Oct 2026 · 09:33:49 UTC Source coverage: cisa-kevIncomplete → Current
- 23 Oct 2026 · 09:33:49 UTC Source coverage: msrc-cvrfIncomplete → Current
- 23 Oct 2026 · 08:31:50 UTC Public exploit codeNo Nuclei template listed → Unknown: exploit-code evidence is incomplete or retained
- 23 Oct 2026 · 08:31:50 UTC CISA KEVNot listed in the collected catalog → Unknown: catalog evidence is incomplete or retained
- 23 Oct 2026 · 08:31:50 UTC Source coverage: public-exploit-codeCurrent → Incomplete
- 23 Oct 2026 · 08:31:50 UTC Source coverage: first-epssCurrent → Incomplete
- 23 Oct 2026 · 08:31:50 UTC Source coverage: cisa-kevCurrent → Incomplete
Show 2 more recent changes
- 23 Oct 2026 · 08:31:50 UTCSource coverage: msrc-cvrf Current → Incomplete
- 21 Oct 2026 · 20:45:25 UTCLast revised 20 Oct 2026 01:09 UTC → 21 Oct 2026 18:33 UTC
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Explore global source statements, affected packages and advisory history for CVE-2026-98454. The catalog has a separate collection scope from Microsoft release records.
Collected exploitation and prediction evidence
Risk source coverageCISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.
No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.
cve-program · CVE-2026-98454
Publishedsmb: client: fix create context out-of-bounds reads
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.
- Source published
- 18 Oct 2026 15:15:04 UTC
- Source modified
- 24 Oct 2026 14:08:54 UTC
- Observed here
- 24 Oct 2026 16:17:04 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS 3.1 · 8.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H