CVE-2026-90061
netfilter: nf_tables: skip double clone set expressions on element insert
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.
INFO
Published Date :
Sept. 17, 2026, 5:16 p.m.
Last Modified :
Sept. 17, 2026, 5:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to resolve the double clone issue.
- Apply the provided patch for nf_tables set expressions.
- Review netfilter module refcount for connlimit expression.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-90061.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/1e7fb6801d9cc826adcdb7fa0533c397730657f2 | |
| https://git.kernel.org/stable/c/43559058d21e0493aa220ac167e0279334dea5f9 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-90061 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-90061
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-90061 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-90061 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 17, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/90xxx/CVE-2026-90061.json">CVE-2026-90061</a> Added Reference https://git.kernel.org/stable/c/1e7fb6801d9cc826adcdb7fa0533c397730657f2 Added Reference https://git.kernel.org/stable/c/43559058d21e0493aa220ac167e0279334dea5f9