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CVE Record

CVE-2026-31548: wifi: cfg80211: cancel pmsr_free_wk in cfg80211_pmsr_wdev_down

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: cancel pmsr_free_wk in cfg80211_pmsr_wdev_down When the nl80211 socket that originated a PMSR request is closed, cfg80211_release_pmsr() sets the request's nl_portid to zero and schedules pmsr_free_wk to process the abort asynchronously. If the interface is concurrently torn down before that work runs, cfg80211_pmsr_wdev_down() calls cfg80211_pmsr_process_abort() directly. However, the already- scheduled pmsr_free_wk work item remains pending and may run after the interface has been removed from the driver. This could cause the driver's abort_pmsr callback to operate on a torn-down interface, leading to undefined behavior and potential crashes. Cancel pmsr_free_wk synchronously in cfg80211_pmsr_wdev_down() before calling cfg80211_pmsr_process_abort(). This ensures any pending or in-progress work is drained before interface teardown proceeds, preventing the work from invoking the driver abort callback after the interface is gone.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A timing flaw in Linux Wi-Fi request cleanup can let delayed kernel work access a wireless interface after teardown. This may cause undefined behavior or crash the system. Exploitation requires local, low-privileged access and specific concurrent events; the supplied evidence does not show active exploitation.

Executive priority

Treat this as a high-priority kernel maintenance issue for Linux endpoints with wireless capability, especially shared or locally accessible systems. Expedite validated vendor updates, but an emergency internet-wide response is not supported because the attack is local and active exploitation is not evidenced.

Technical view

When a PMSR-originating nl80211 socket closes, asynchronous pmsr_free_wk cleanup can race with cfg80211 interface teardown. The pending worker may later invoke the driver's abort_pmsr callback on a removed interface. The stable fixes synchronously cancel and drain that work before processing the abort.

Likely exposure

Exposure is most likely on affected Linux systems using cfg80211 Wi-Fi and drivers implementing PMSR abort handling. Trigger conditions require local access, a PMSR request, socket closure, and concurrent interface teardown. Exact distribution exposure depends on backports; the supplied version data cannot reliably map every vendor kernel.

Exploitation context

CVSS 3.1 is 7.8: local, low complexity, low privileges, and no user interaction, with potentially high impact. The supplied record marks KEV false and provides no evidence of active exploitation or a public exploit. The documented consequence is undefined behavior, including possible crashes.

Researcher notes

This is a race between asynchronous PMSR cleanup and wireless-interface teardown. The fix synchronously cancels and drains pmsr_free_wk before directly processing the abort. Sources establish the flaw and stable commits, but do not demonstrate reliable privilege escalation, data disclosure, or code execution.

Mitigation direction

  • Apply a vendor-supplied Linux kernel update containing the applicable cited stable fix.
  • Confirm distribution advisory and backport status instead of relying solely on upstream version numbers.
  • Prioritize Wi-Fi-enabled endpoints where local untrusted users or applications can access nl80211.
  • If patching is delayed, consult vendor guidance; the supplied sources identify no tested workaround.

Validation and detection

  • Inventory kernel packages and builds across Wi-Fi-enabled Linux assets.
  • Check vendor changelogs or kernel source for the applicable cited stable fix.
  • Confirm whether cfg80211 and relevant wireless drivers are present on each system.
  • Review kernel logs for cfg80211, PMSR, interface-teardown warnings, or unexplained crashes.
Prepared
Confidence
medium
Sources
8

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

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CVE-2026-31548 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/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
0ADP providers
7Source links

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
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-31548Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux9bb7e0f24e7e7d00daa1219b14539e2e602649b2, 9bb7e0f24e7e7d00daa1219b14539e2e602649b2, 9bb7e0f24e7e7d00daa1219b14539e2e602649b2, 9bb7e0f24e7e7d00daa1219b14539e2e602649b2, 9bb7e0f24e7e7d00daa1219b14539e2e602649b2, 9bb7e0f24e7e7d00daa1219b14539e2e602649b2unaffected
LinuxLinux5.0, 0, 6.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10, 7.0affected
Weakness

CWE details

No CWE listed

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