netfilter: nf_tables: skip double clone set expressions on element insert (CVE-2026-90061) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-90061

netfilter: nf_tables: skip double clone set expressions on element insert

Answer in brief

CVE-2026-90061 records a Unknown severity vulnerability in netfilter: nf_tables: skip double clone set expressions on element insert. 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	>=65038428b2c6c5be79d3f78a6b79c0cdc3a58a41 <1e7fb6801d9cc826adcdb7fa0533c397730657f2 \|\| >=65038428b2c6c5be79d3f78a6b79c0cdc3a58a41 <43559058d21e0493aa220ac167e0279334dea5f9	1e7fb6801d9cc826adcdb7fa0533c397730657f2, 43559058d21e0493aa220ac167e0279334dea5f9
Linux/Linuxgeneric	5.7	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 1e7fb6801d9cc826adcdb7fa0533c397730657f2 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: netfilter: nf_tables: skip double clone set expressions on element insert Both the dynset and newsetelem path clone the existing set expressions when setting set element expressions if no override expressions are provided. This results in a double clone, once to clone the template set expressions then another clone on the new element. Add a flag to annotate if userspace provides a override expression (ie. expression of the same type of the set but different configuration), otherwise borrow the existing expression from the set. Add conditionals to release expression iif they represent an override. Use this new override_exprs flag to dump the dynset expression override to userspace. This simplifies the existing logic and it also fixes a bug with the connlimit expression which results in a module refcount imbalance WARNING splat when resorting on the default set expressions.

Quoted source text, attributed separately from HOL analysis.