CVE-2026-23139
Denial of Service via Memory Leak in Linux netfilter nf_conncount
Publication date: 2026-02-14
Last updated on: 2026-04-03
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | From 6.13 (inc) to 6.18.6 (exc) |
| linux | linux_kernel | From 6.2 (inc) to 6.6.121 (exc) |
| linux | linux_kernel | From 6.7 (inc) to 6.12.66 (exc) |
| linux | linux_kernel | From 5.19 (inc) to 6.1.161 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Linux kernel's netfilter component, specifically in the nf_conncount module. The issue is that the variable last_gc, which tracks the last garbage collection (GC) time, is updated every time a new network connection is tracked, regardless of whether a GC was actually performed.
Because last_gc is updated even without performing GC, an attacker can send packets at a high rate to continuously bypass the garbage collection process. This causes the internal list that tracks connections to grow without limit, potentially leading to resource exhaustion.
The fix involves updating last_gc only when a garbage collection has actually been performed, preventing the list from growing infinitely.
How can this vulnerability impact me? :
This vulnerability can lead to resource exhaustion in the Linux kernel's netfilter subsystem by allowing the connection tracking list to grow infinitely.
An attacker could exploit this by sending a high rate of packets, causing the system to consume excessive memory or processing resources, potentially leading to degraded performance or denial of service.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know