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CVE Record

CVE-2024-26936: ksmbd: validate request buffer size in smb2_allocate_rsp_buf()

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate request buffer size in smb2_allocate_rsp_buf() The response buffer should be allocated in smb2_allocate_rsp_buf before validating request. But the fields in payload as well as smb2 header is used in smb2_allocate_rsp_buf(). This patch add simple buffer size validation to avoid potencial out-of-bounds in request buffer.

HighCVSS 8.2Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A malformed SMB request can make the Linux kernel's ksmbd file-sharing server read beyond the request buffer. An unauthenticated remote attacker could potentially disrupt service and expose limited information. The supplied CVSS score is 8.2, driven primarily by high availability impact.

Executive priority

Prioritize exposed ksmbd servers for prompt remediation, especially internet-facing or broadly reachable file servers. Treat internal systems according to SMB reachability and service criticality. This is high priority, but the supplied sources do not justify declaring an active exploitation emergency.

Technical view

smb2_allocate_rsp_buf() used fields from the SMB2 header and payload before adequately validating request size. The kernel fix adds buffer-size validation to prevent potential out-of-bounds access while allocating a response buffer. The supplied vector indicates network reachability, low complexity, no privileges, and no user interaction.

Likely exposure

Exposure is most likely where an affected Linux kernel runs ksmbd and accepts SMB traffic from untrusted networks. Systems without ksmbd enabled or reachable have substantially lower practical exposure. The supplied version data is ambiguous, so distribution-specific package status should determine applicability.

Exploitation context

The bundle reports no CISA KEV listing and provides no evidence of active exploitation or a public exploit. Remote, unauthenticated reachability increases theoretical exploitability, but the supplied evidence supports only potential out-of-bounds access, limited confidentiality impact, and high availability impact.

Researcher notes

The record identifies request-size validation as the root issue but provides no CWE, crash trace, proof of concept, or confirmed exploit behavior. The affected-version list is not sufficiently clear for exact range conclusions. Use the five stable-kernel commits and distribution advisories to establish branch-specific remediation.

Mitigation direction

  • Install the distribution-supported kernel update containing the applicable referenced fix.
  • If immediate patching is impossible, restrict SMB access to trusted networks.
  • Disable ksmbd where kernel-based SMB service is unnecessary.
  • Review Linux vendor advisories for precise package and backport status.

Validation and detection

  • Confirm whether ksmbd is enabled or loaded on each Linux system.
  • Identify the running kernel and distribution package release.
  • Compare vendor package status with the referenced stable-kernel fixes.
  • Verify SMB exposure from untrusted and internet-facing networks.
  • After updating, confirm the corrected kernel is running.
Prepared
Confidence
medium
Sources
7

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

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CVE-2024-26936 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.2 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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
6Source 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
8.2CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H3.94.2Linux

Vulnerability scoring details

Base CVSS 3.1 score

8.2High
CVSS 3.1 vector shape for CVE-2024-26936Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux0626e6641f6b467447c81dd7678a69c66f7746cf, 0626e6641f6b467447c81dd7678a69c66f7746cf, 0626e6641f6b467447c81dd7678a69c66f7746cf, 0626e6641f6b467447c81dd7678a69c66f7746cf, 0626e6641f6b467447c81dd7678a69c66f7746cfunaffected
LinuxLinux5.15, 0, 5.15.159, 6.1.88, 6.6.29, 6.8.8, 6.9affected
Weakness

CWE details

No CWE listed

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