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CVE Record

CVE-2024-26954: ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16() If ->NameOffset of smb2_create_req is smaller than Buffer offset of smb2_create_req, slab-out-of-bounds read can happen from smb2_open. This patch set the minimum value of the name offset to the buffer offset to validate name length of smb2_create_req().

HighCVSS 8.1Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A malformed SMB2 create request can make Linux's in-kernel SMB server, ksmbd, read beyond allocated memory. The supplied CVSS score is 8.1, with potentially high confidentiality and availability impact. Organizations actively using ksmbd should prioritize patched kernels; systems not running the service are less likely exposed.

Executive priority

Treat as a high-priority kernel update for systems actively providing SMB through ksmbd, especially across broad network boundaries. Prioritize exposure confirmation immediately and remediation through supported kernel packages. Lower the priority only after confirming ksmbd is inactive, unreachable, or the vendor kernel already contains the fix.

Technical view

In smb2_open, a NameOffset smaller than smb2_create_req's Buffer offset can cause smb_strndup_from_utf16() to perform a slab out-of-bounds read during name validation. The fix enforces the Buffer offset as the minimum name offset before calculating the request name length. CVSS indicates network access, low complexity, low privileges, and no user interaction.

Likely exposure

Exposure is most likely where ksmbd is enabled, serving SMB, reachable over a network, and running an affected kernel build. Affected-version data in the bundle is ambiguous, so distribution backports and patch presence must be checked. Merely having Linux installed does not establish exposure.

Exploitation context

The bundle marks this CVE as absent from KEV and provides no cited evidence of active exploitation or public exploit availability. This is not proof that exploitation has never occurred. Network reachability and low attack complexity increase concern, although the CVSS vector indicates low privileges are required.

Researcher notes

The affected-version data is insufficiently structured to establish exact vulnerable ranges; it mixes release identifiers and repeated commit hashes. Validate vendor backports through advisories or code presence rather than version strings alone. The source bundle identifies no CWE, and it does not establish exploitation in the wild.

Mitigation direction

  • Update to a vendor-supported kernel release containing the applicable Linux stable fix or equivalent backport.
  • Prioritize hosts where ksmbd serves SMB across untrusted or broadly accessible networks.
  • Until updated, restrict ksmbd SMB reachability to required clients using existing network controls.
  • Follow distribution security advisories for packaged kernel versions and backport status.

Validation and detection

  • Inventory kernel versions and determine whether ksmbd is enabled and serving SMB.
  • Compare each kernel package against its distribution advisory and documented backport status.
  • Verify the applicable stable fix or equivalent code change is present after updating.
  • Confirm network controls limit SMB reachability to required clients.
Prepared
Confidence
medium
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2024-26954 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.1 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
2ADP providers
7Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.1CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H2.85.2Linux

Vulnerability scoring details

Base CVSS 3.1 score

8.1High
CVSS 3.1 vector shape for CVE-2024-26954Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux0626e6641f6b467447c81dd7678a69c66f7746cf, 0626e6641f6b467447c81dd7678a69c66f7746cf, 0626e6641f6b467447c81dd7678a69c66f7746cf, 0626e6641f6b467447c81dd7678a69c66f7746cf, 0626e6641f6b467447c81dd7678a69c66f7746cfunaffected
LinuxLinux5.15, 0, 6.1.119, 6.6.32, 6.7.12, 6.8.3, 6.9affected
Weakness

CWE details

No CWE listed

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