LiveActive security incident?Get immediate response
CVE Record

CVE-2026-43112: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath

In the Linux kernel, the following vulnerability has been resolved: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath When cifs_sanitize_prepath is called with an empty string or a string containing only delimiters (e.g., "/"), the current logic attempts to check *(cursor2 - 1) before cursor2 has advanced. This results in an out-of-bounds read. This patch adds an early exit check after stripping prepended delimiters. If no path content remains, the function returns NULL. The bug was identified via manual audit and verified using a standalone test case compiled with AddressSanitizer, which triggered a SEGV on affected inputs.

HighCVSS 8.8Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-43112 is a Linux kernel SMB/CIFS client flaw. A malformed or empty path can make the kernel read memory outside the intended buffer. The CVE rates it high severity, but the supplied sources do not show active exploitation.

Executive priority

Treat this as a high-priority kernel maintenance issue for Linux environments that use SMB/CIFS. Prioritize patch validation over emergency response unless new evidence shows exploitation or broader vendor impact.

Technical view

The flaw is in fs/smb/client cifs_sanitize_prepath. After stripping leading delimiters, empty or delimiter-only input can cause a check of cursor2 - 1 before cursor2 advances, triggering an out-of-bounds read. The fix adds an early return when no path content remains.

Likely exposure

Exposure is most relevant to Linux systems running affected kernels with SMB/CIFS client functionality. The source lists Linux kernel versions and multiple stable commits, but distribution impact should be confirmed against vendor advisories and package status.

Exploitation context

The source says the bug was found by manual audit and verified with an AddressSanitizer standalone test causing a SEGV. KEV is false, and no cited source in the bundle states active exploitation.

Researcher notes

The evidence supports CWE-125 out-of-bounds read in cifs_sanitize_prepath. The affected-version list in the bundle is unusual, with commit hashes and version values mixed, so validate exposure using upstream commits and vendor advisories.

Mitigation direction

  • Apply kernel updates that include the referenced stable fixes.
  • For Red Hat systems, follow the listed RHSA advisories and VEX status.
  • Prioritize systems using SMB/CIFS client mounts or workflows.
  • If patching is delayed, check vendor guidance for supported temporary controls.

Validation and detection

  • Inventory Linux kernel versions across servers, workstations, and appliances.
  • Identify hosts using SMB/CIFS client functionality.
  • Confirm installed kernels include the relevant stable fix or vendor erratum.
  • Review Red Hat CVE, Bugzilla, CSAF VEX, and RHSA entries for product status.
Prepared
Confidence
medium
Sources
12

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-125: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-43112 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
8.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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.

2CVSS vectors
5Timeline events
1ADP providers
15Source links

CVSS vector scores

2 official scores

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
8.8CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9Linux
8.1CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H2.85.2redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

8.8High
CVSS 3.1 vector shape for CVE-2026-43112Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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. ADP timelineredhat-SADP

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

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

ADP provider summaries

redhat-SADPkernel: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath
other:Red Hat severity ratingcvssV3_1
  • 2026-05-06T00:00:00.000Z: Reported to Red Hat.
  • 2026-05-06T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxc63433a09d6ae4c226fcbc66da4c58fc189fd746, a31080899d5fdafcccf7f39dd214a814a2c82626, a31080899d5fdafcccf7f39dd214a814a2c82626, a31080899d5fdafcccf7f39dd214a814a2c82626, a31080899d5fdafcccf7f39dd214a814a2c82626, a31080899d5fdafcccf7f39dd214a814a2c82626, a31080899d5fdafcccf7f39dd214a814a2c82626, 5.15.11unaffected
LinuxLinux5.16, 0, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0affected
Weakness

CWE details

CWE-125

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-125 · source CWE mapping

Out-of-bounds Read

Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs