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Linux KernelOperating system · Linux

CVE-2026-23139

MEDIUM · 5.5 CVSS v3.1 Published 2026-02-14
Fix available
A fix is available. Upgrade to 6.1.161 / 6.6.121 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 5.19, < 6.1.161>= 6.2, < 6.6.121>= 6.7, < 6.12.66>= 6.13, < 6.18.6= 6.19

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.1.161 / 6.6.121 / 6.12.66 or later
Fixed in 6.1.1616.6.1216.12.66
Vendor patch git.kernel.org →
Recommended fix High confidence

Upgrade to kernel 6.1.161+, 6.6.121+, 6.12.66+, or 6.18.6+ depending on your current branch

  1. Identify the current kernel version using `uname -r`
  2. Determine which stable branch you are on (6.1.x, 6.2.x, 6.6.x, 6.7.x, 6.12.x, or 6.13.x+)
  3. Upgrade the Linux kernel to the first fixed version in your branch: for 6.1.x series upgrade to >= 6.1.161, for 6.2.x upgrade to >= 6.6.121 (note: 6.2 is EOL, migrate to 6.6 LTS), for 6.6.x upgrade to >= 6.6.121, for 6.7.x upgrade to >= 6.12.66, for 6.12.x upgrade to >= 6.12.66, for 6.13.x or 6.14.x upgrade to >= 6.18.6
  4. Use your distribution's package manager to install the updated kernel (e.g., `apt update && apt upgrade` for Debian/Ubuntu, `dnf update` for Fedora/RHEL, or `zypper update` for SUSE)
  5. Reboot the system to load the new kernel
  6. Verify the new kernel version is running with `uname -r`
Caveat Kernel upgrades may introduce regressions; ensure critical drivers and modules are compatible with the new version before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-23139 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data