Security readout for executives and security teams
Plain-English summary
A Linux kernel dcache flaw can read outside allocated kernel memory when the dentry hash table is configured with only one bucket. The documented failure is a kernel page fault, creating serious availability risk and possible exposure of kernel memory. The supplied record rates it critical, although practical remote reachability is not established by the technical description.
Executive priority
Treat as an urgent verification and patching task because kernel crashes and potential kernel-memory disclosure carry high impact. Prioritize confirmed affected configurations. Current sources do not justify declaring an active internet-wide emergency, because exploitation is not documented and the stated network vector is not reconciled with the configuration prerequisite.
Technical view
Setting dhash_entries=1 creates one dentry hash bucket and causes d_hash_shift to become 32. A 32-bit value is then shifted by 32, producing undefined behavior that can calculate an unallocated bucket address. __d_lookup subsequently performs an out-of-bounds read. The fix enforces a minimum of two buckets.
Likely exposure
Exposure requires an affected Linux kernel and the dhash_entries=1 configuration described by the source. The supplied affected-version data is complex and includes commit identifiers, so determine status through the system's distribution or kernel vendor rather than version-string comparison alone.
Exploitation context
The bundle marks this CVE as absent from KEV and provides no evidence of active exploitation or a public exploit. Although the supplied CVSS vector claims unauthenticated network reachability, the technical description depends on a kernel configuration value. How a remote attacker could establish or exploit that condition is not explained.
Researcher notes
The demonstrated path is d_lookup through d_hash into hlist traversal, ending in an out-of-bounds read from an unallocated hash bucket. Undefined shift behavior is central. Sources demonstrate a kernel fault but do not establish controlled data disclosure, code execution, remote triggerability, or attacker ability to set dhash_entries.
Mitigation direction
- Apply the distribution or kernel vendor update incorporating the referenced minimum-two-bucket fix.
- Prioritize systems confirmed to use dhash_entries=1 or otherwise matching vendor-affected builds.
- Where updating is delayed, remove dhash_entries=1 after approved testing and vendor confirmation.
- Monitor Linux distribution advisories for precise package and supported-branch remediation details.
Validation and detection
- Inventory running kernel releases and package builds across Linux systems.
- Check bootloader and kernel configuration sources for dhash_entries=1.
- Confirm installed packages contain the applicable referenced stable-kernel fix.
- Reboot updated systems where required, then verify the running kernel matches the remediated package.
- Review kernel logs for dcache-related page faults or crashes; absence does not prove safety.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-2026-43071 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
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.
CVSS vector scores
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H3.95.2LinuxVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/45b06bb5ea96f75ad81d7ef446f832ea6b0026feCVE reference, Linux
- https://git.kernel.org/stable/c/426ef05e82ee52c8d0e95fc0808b7383d8352d73CVE reference, Linux
- https://git.kernel.org/stable/c/ddd57ebce245f9c7e2f6902a6c087d6186d2385dCVE reference, Linux
- https://git.kernel.org/stable/c/755b40903eff563768d4d96fd4ef51ec48adde3bCVE reference, Linux
- https://git.kernel.org/stable/c/5718df131ab78897a9dd1f2e71c3ba732d4392afCVE reference, Linux
- https://git.kernel.org/stable/c/277cedabb0ab86baae83fa58218be13c6d3e5526CVE reference, Linux
- https://git.kernel.org/stable/c/f08fe8891c3eeb63b73f9f1f6d97aa629c821579CVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.