# CVE-2026-45860: netfilter: nf_conncount: increase the connection clean up limit to 64

> Attackers can cause connection tracking limits to be reached prematurely, leading to service unavailability in Linux kernel netfilter configurations.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 May 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-45860, DEBIAN-CVE-2026-45860, GHSA-xwf3-wjqg-p85x, ROOT-OS-DEBIAN-11-CVE-2026-45860, ROOT-OS-UBUNTU-2204-CVE-2026-45860, ROOT-OS-UBUNTU-2404-CVE-2026-45860, UBUNTU-CVE-2026-45860

## What is CVE-2026-45860?

CVE-2026-45860 is a high-severity denial of service vulnerability in Linux kernel, published on 27 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conncount: increase the connection clean up limit to 64

After the optimization to only perform one GC per jiffy, a new problem
was introduced. If more than 8 new connections are tracked per jiffy the
list won't be cleaned up fast enough possibly reaching the limit
wrongly.

In order to prevent this issue, only skip the GC if it was already
triggered during the same jiffy and the increment is lower than the
clean up limit. In addition, increase the clean up limit to 64
connections to avoid triggering GC too often and do more effective GCs.

This has been tested using a HTTP server and several
performance tools while having nft_connlimit/xt_connlimit or OVS limit
configured.

Output of slowhttptest + OVS limit at 52000 connections:

 slow HTTP test status on 340th second:
 initializing:        0
 pending:             432
 connected:           51998
 error:               0
 closed:              0
 service available:   YES

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-45860?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-45860?

Apply the vendor's patch.

## Is CVE-2026-45860 being exploited?

There is no known exploitation of CVE-2026-45860 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45860 and fix it if it is affected.

What it is: CVE-2026-45860 is a high-severity denial of service vulnerability in Linux kernel, published on 27 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45860 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-45860/ (Markdown: https://insights.sbomify.com/CVE-2026-45860/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45860
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45860
- OSV: https://osv.dev/vulnerability/CVE-2026-45860

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45860/
Summaries are generated and may contain mistakes; the official description above is the record.