Security readout for executives and security teams
Plain-English summary
This Linux kernel issue affects SoundWire controller detection in the ALSA HDA ACPI path. The kernel could record a controller pointer before confirming it was actually a SoundWire controller, causing later detection logic to fail. The public record does not describe data theft, privilege escalation, remote exploitation, or active exploitation.
Executive priority
Handle as routine kernel hygiene unless affected endpoint fleets depend on this hardware path. There is no sourced evidence of active exploitation or severe business impact, but unsupported or custom kernels should still be corrected through normal patch governance.
Technical view
The flaw is in intel-sdw-acpi controller discovery. The prior logic populated caller-visible information before validating the ACPI handle as a SoundWire controller. The fix delays setting that information until a controller is found. Affected kernel information is listed for Linux, including 5.3-era through fixed stable releases, but impact details are sparse.
Likely exposure
Exposure appears limited to Linux systems using the affected kernel code path for Intel HDA/SoundWire ACPI detection. The strongest candidates are laptops or endpoints with relevant audio hardware on affected kernel versions. Server exposure is likely lower unless that hardware and driver path are present.
Exploitation context
CISA KEV is false in the provided bundle, and no cited source states active exploitation. The available description points to detection failure behavior, not a documented exploit technique or attacker-controlled path. Treat exploitation context as unproven from these sources.
Researcher notes
The CVE record is sparse: no CVSS, CWE, exploit status, or detailed impact class is provided. Analysis should stay close to the upstream fix: incorrect early population of caller-visible ACPI controller information during graph traversal, corrected by setting it only after controller discovery.
Mitigation direction
- Check Linux vendor advisories for backported fixes covering CVE-2021-46926.
- Update affected Linux kernels to a fixed vendor-supported release.
- Prioritize systems with Intel HDA or SoundWire ACPI audio hardware.
- Track the referenced stable kernel commits in kernel-source-based environments.
- Document accepted risk where affected hardware paths are not present.
Validation and detection
- Inventory kernel versions against vendor fixed-version guidance.
- Confirm the fix is present through vendor package notes or source commit history.
- Identify endpoints using Intel HDA or SoundWire ACPI audio paths.
- Review fleet exceptions for unsupported or custom kernels.
- Record that no KEV listing was provided in the source bundle.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-46926 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
SSVC decision data
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.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/cce476954401e3421afafb25bbaa926050688b1dCVE reference, Linux
- https://git.kernel.org/stable/c/385f287f9853da402d94278e59f594501c1d1dadCVE 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.