Bug 2439874 (CVE-2026-23139)

Summary: CVE-2026-23139 kernel: netfilter: nf_conncount: update last_gc only when GC has been performed
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-02-14 16:02:49 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conncount: update last_gc only when GC has been performed

Currently last_gc is being updated everytime a new connection is
tracked, that means that it is updated even if a GC wasn't performed.
With a sufficiently high packet rate, it is possible to always bypass
the GC, causing the list to grow infinitely.

Update the last_gc value only when a GC has been actually performed.
Comment 1 Alexander B 2026-02-16 13:27:19 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026021429-CVE-2026-23139-a7b4@gregkh/T