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CVE Record

CVE-2024-26811: ksmbd: validate payload size in ipc response

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate payload size in ipc response If installing malicious ksmbd-tools, ksmbd.mountd can return invalid ipc response to ksmbd kernel server. ksmbd should validate payload size of ipc response from ksmbd.mountd to avoid memory overrun or slab-out-of-bounds. This patch validate 3 ipc response that has payload.

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

A malicious or compromised ksmbd-tools installation could make its user-space mount daemon send malformed responses to the Linux ksmbd server. Missing size checks could then cause kernel memory corruption or out-of-bounds access, potentially affecting confidentiality, integrity, and availability.

Executive priority

Prioritize investigation and patching on Linux systems actively using ksmbd, especially exposed file servers or systems with uncertain package provenance. The potential kernel-memory impact is severe, but the documented malicious-tools prerequisite means urgency should be based on confirmed ksmbd use and trusted software-supply controls.

Technical view

The ksmbd kernel server did not adequately validate payload sizes in three IPC responses received from ksmbd.mountd. Invalid responses could trigger a memory overrun or slab out-of-bounds condition. Linux stable commits add the missing validation. The supplied CVSS score is 9.8, although the stated malicious-tools prerequisite materially affects practical exposure.

Likely exposure

Exposure is most likely where affected Linux kernels use ksmbd alongside a malicious, compromised, or otherwise untrusted ksmbd-tools installation. Systems not using ksmbd are less likely to be reachable through the described path. The supplied version data is ambiguous, so exact distribution package status requires vendor confirmation.

Exploitation context

The source bundle does not identify CVE-2024-26811 in CISA KEV and provides no evidence of active exploitation. Although the CVSS vector describes unauthenticated network reachability, the vulnerability description specifically requires malicious ksmbd-tools producing invalid IPC responses. Treat that discrepancy as an important qualification.

Researcher notes

The central issue is trust-boundary validation between ksmbd.mountd and the kernel server, resulting in possible memory overrun or slab out-of-bounds access. The bundle identifies five stable-kernel commits but gives unclear affected-version semantics. Researchers should avoid inferring remote exploitability solely from the CVSS vector because the narrative names malicious ksmbd-tools as the trigger.

Mitigation direction

  • Identify systems running the listed Linux kernel branches and determine whether ksmbd is used.
  • Apply vendor-supported kernel updates containing the referenced IPC payload-size validation changes.
  • Check Linux distribution advisories for exact corrected package versions before deployment.
  • Use trusted, verified sources for ksmbd-tools and investigate unexpected or unauthorized installations.

Validation and detection

  • Inventory deployed kernel and ksmbd-tools package versions on systems providing SMB services.
  • Confirm whether ksmbd is installed, enabled, or actively serving shares.
  • Compare exact package builds with Linux stable commits and applicable distribution advisories.
  • Verify updated kernels include validation for all three payload-bearing IPC responses.
  • Review package provenance and integrity records for evidence of untrusted ksmbd-tools installation.
Prepared
Confidence
medium
Sources
10

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.

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CVE-2024-26811 mapping review

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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
9Source 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
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2024-26811Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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, 5.15.157, 6.1.85, 6.6.26, 6.8.5, 6.9affected
Weakness

CWE details

No CWE listed

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