cifs: validate idmap key payload length

Answer in brief

CVE-2026-93785 records a Unknown severity vulnerability in cifs: validate idmap key payload length. The current sources do not mark it as known exploited. The current feed maps 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 24, 2026Updated Sep 24, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 24, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
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). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6cfeef221ac00d63c07f6122f58e6159bde69ca0 \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b12f65d7caf16d124098cb4895a203367d35b57 \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <455488cd5054bcc59db40fa1cc2c004031a5b2a5 \|\| >=0 <6.12.111 \|\| >=0 <6.18.53	6cfeef221ac00d63c07f6122f58e6159bde69ca0, 8b12f65d7caf16d124098cb4895a203367d35b57, 455488cd5054bcc59db40fa1cc2c004031a5b2a5, 6.12.111, 6.18.53

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux.
Review the reported fix. Update Linux/Linux to 6cfeef221ac00d63c07f6122f58e6159bde69ca0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: cifs: validate idmap key payload length The cifs.idmap key type stores its payload length in key->datalen, which is limited to U16_MAX. Accepting a larger key payload truncates the recorded length and can make later users interpret the payload using inconsistent bounds. Reject oversized preparsed payloads before allocating or copying them. This keeps key->datalen consistent with the stored data for both inline and separately allocated idmap payloads.

Quoted source text, attributed separately from HOL analysis.