LiveActive security incident?Get immediate response
CVE Record

CVE-2025-38509: wifi: mac80211: reject VHT opmode for unsupported channel widths

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: reject VHT opmode for unsupported channel widths VHT operating mode notifications are not defined for channel widths below 20 MHz. In particular, 5 MHz and 10 MHz are not valid under the VHT specification and must be rejected. Without this check, malformed notifications using these widths may reach ieee80211_chan_width_to_rx_bw(), leading to a WARN_ON due to invalid input. This issue was reported by syzbot. Reject these unsupported widths early in sta_link_apply_parameters() when opmode_notif is used. The accepted set includes 20, 40, 80, 160, and 80+80 MHz, which are valid for VHT. While 320 MHz is not defined for VHT, it is allowed to avoid rejecting HE or EHT clients that may still send a VHT opmode notification.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This Linux kernel Wi-Fi issue lets malformed VHT operating mode notifications reach code that expects only valid channel widths. The known result is a kernel warning, not confirmed compromise. Systems using affected Linux kernels with mac80211 Wi-Fi support should receive normal kernel security updates.

Executive priority

Handle through standard kernel patch management unless your environment depends heavily on Linux Wi-Fi clients or appliances. There is no source-backed evidence of active exploitation or severe impact in the provided bundle.

Technical view

mac80211 did not reject VHT operating mode notifications for unsupported 5 MHz or 10 MHz widths. Those invalid widths could reach ieee80211_chan_width_to_rx_bw() and trigger a WARN_ON. The fix rejects unsupported widths early in sta_link_apply_parameters() while allowing valid VHT widths.

Likely exposure

Exposure is most relevant to Linux systems using Wi-Fi/mac80211 on affected kernel versions. Servers without Wi-Fi hardware or mac80211 usage are less likely to be exposed, based on the supplied description.

Exploitation context

The bundle says syzbot reported the issue. It does not cite active exploitation, public exploit activity, KEV listing, privilege impact, or confirmed denial-of-service beyond the WARN_ON behavior.

Researcher notes

The evidence supports an input-validation bug in mac80211 VHT operating mode handling. The supplied sources do not provide CVSS, CWE, exploitability analysis, or a broader impact claim. Treat impact beyond kernel WARN_ON as unproven from this bundle.

Mitigation direction

  • Update to a kernel containing the referenced stable fixes.
  • Prioritize affected systems with active Wi-Fi/mac80211 use.
  • Check your Linux vendor advisories for backported fixes.
  • Avoid assuming fixed status from version numbers alone on vendor kernels.

Validation and detection

  • Inventory Linux kernel versions across Wi-Fi-capable assets.
  • Check whether mac80211-based wireless interfaces are present and enabled.
  • Confirm installed kernels include the referenced stable commits or vendor backports.
  • Review kernel logs for related WARN_ON reports if suspicious Wi-Fi behavior occurred.
Prepared
Confidence
medium
Sources
4

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.

cve · low confidence lookup

CVE-2025-38509 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
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
3Timeline events
0ADP providers
3Source links

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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux751e7489c1d74b94ffffbed619d8fd724eeff4ee, 751e7489c1d74b94ffffbed619d8fd724eeff4eeunaffected
LinuxLinux6.13, 0, 6.15.7, 6.16affected
Weakness

CWE details

No CWE listed

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