ksmbd: free preauth sessions on connection teardown (CVE-2026-90169) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-90169

ksmbd: free preauth sessions on connection teardown

Answer in brief

CVE-2026-90169 records a Unknown severity vulnerability in ksmbd: free preauth sessions on connection teardown. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=f5a544e3bab78142207e0242d22442db85ba1eff <effcf48d79d8aa53113d8289e140746f25ceb62c \|\| >=f5a544e3bab78142207e0242d22442db85ba1eff <b62b1ebb25f0a19067ed5b1a86036b2dc98be44f \|\| >=f5a544e3bab78142207e0242d22442db85ba1eff <a41a98ee16ae038751b6639decadaa3ce15ca18a \|\| >=f5a544e3bab78142207e0242d22442db85ba1eff <8e2ebc77678832e981adc008d25cd8f67d08ebc4 \|\| >=f5a544e3bab78142207e0242d22442db85ba1eff <06c7b1d731bc105a8644f1b70165ba8b9416cbab	effcf48d79d8aa53113d8289e140746f25ceb62c, b62b1ebb25f0a19067ed5b1a86036b2dc98be44f, a41a98ee16ae038751b6639decadaa3ce15ca18a, 8e2ebc77678832e981adc008d25cd8f67d08ebc4, 06c7b1d731bc105a8644f1b70165ba8b9416cbab
Linux/Linuxgeneric	5.15	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to effcf48d79d8aa53113d8289e140746f25ceb62c if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: free preauth sessions on connection teardown SMB3.1.1 multichannel binding preserves the preauthentication hash in a preauth_session between the NTLM negotiate and authenticate requests. The binding NTLM negotiate allocates this object and returns STATUS_MORE_PROCESSING_REQUIRED. If the client disconnects before it sends the authenticate request, neither the authenticate nor error cleanup paths free the object. Release any remaining preauthentication sessions when tearing down the connection. Initialize the list when allocating the connection so that this cleanup is safe regardless of the negotiated dialect.

Quoted source text, attributed separately from HOL analysis.