netfilter: nf_conncount: update last_gc only when GC has been performed
Priority LOW 33Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
EPSS 0.00383 32nd percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.1.161, 6.6.121, 6.12.66 +2Red Hat: 1 advisoryRed Hat: 5 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.19 and later | 6.1.161, 6.6.121, 6.12.66, 6.18.6, 6.19 | Patch available | CNA |
- Linux VendorLinux Affected 5.19 and later Fixed in 6.1.161, 6.6.121, 6.12.66, 6.18.6, 6.19 Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.19 to before 6.1.161; 6.2 to before 6.6.121; 6.7 to before 6.12.66; 6.13 to before 6.18.6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* | 6.19 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* | 6.19 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* | 6.19 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* | 6.19 rc4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.19 to before 6.1.161; 6.2 to before 6.6.121; 6.7 to before 6.12.66; 6.13 to before 6.18.6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* Versions 6.19 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* Versions 6.19 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* Versions 6.19 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* Versions 6.19 rc4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.161, 6.6.121, 6.12.66, 6.18.6, 6.19
Red Hat 1 advisory
- RHSA-2026:15883 Released 2026-05-11 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.72.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.72.1.el10_0, kernel-64k-devel-6.12.0-55.72.1.el10_0 +12
- Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.72.1.el10_0, kernel-64k-6.12.0-55.72.1.el10_0, kernel-64k-core-6.12.0-55.72.1.el10_0 +28
- Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.72.1.el10_0, libperf-6.12.0-55.72.1.el10_0
- Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.72.1.el10_0, kernel-rt-64k-6.12.0-55.72.1.el10_0, kernel-rt-64k-core-6.12.0-55.72.1.el10_0 +21
- Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.72.1.el10_0, kernel-rt-core-6.12.0-55.72.1.el10_0, kernel-rt-debug-6.12.0-55.72.1.el10_0 +11
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:15883 |
| Red Hat Enterprise Linux BaseOS EUS (v. 10.0) | Fixed | RHSA-2026:15883 |
| Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) | Fixed | RHSA-2026:15883 |
| Red Hat Enterprise Linux Real Time EUS (v. 10.0) | Fixed | RHSA-2026:15883 |
| Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) | Fixed | RHSA-2026:15883 |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-23139
- 2026-10-03 Alias added: GHSA-cf2j-m586-269w
References
Patch 7
- https://git.kernel.org/stable/c/2c7c71113ed6d3e2f3aca4c088f22283016ff34f
- https://git.kernel.org/stable/c/c4cde57c8affdcca5bcff53a1047e15d268bdca1
- https://git.kernel.org/stable/c/9f45588993d7f115280fc726119ca86fba32a811
- https://git.kernel.org/stable/c/3cd717359e56f82f06cbf8279b47a7d79880c6f3
- https://git.kernel.org/stable/c/26a82dce2beee39c43c109d9647e16f49cb02a35
- https://git.kernel.org/stable/c/8bdafdf4900040a81422056cabe5e00a37bd101a
- https://git.kernel.org/stable/c/7811ba452402d58628e68faedf38745b3d485e3c
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-23139 · CVE Program
- CVE-2026-23139 · NVD
- FIRST EPSS
- GHSA-cf2j-m586-269w · GitHub Advisory Database · CC BY 4.0
- CVE-2026-23139 · Red Hat security data · CC BY 4.0
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