netfilter: conntrack: clamp maximum hashtable size to INT_MAX
Priority LOW 24Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 10 fixed, 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: clamp maximum hashtable size to INT_MAX Use INT_MAX as maximum size for the conntrack hashtable. Otherwise, it is possible to hit WARN_ON_ONCE in __kvmalloc_node_noprof() when resizing hashtable because __GFP_NOWARN is unset. See: 0708a0afe291 ("mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls") Note: hashtable resize is only possible from init_netns.
Why it matters now
EPSS 0.00219 12th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.234, 5.15.177, 6.1.125 +3Red Hat: 2 advisoriesRed Hat: 10 fixed, 4 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 | 4.7 and later | 5.10.234, 5.15.177, 6.1.125, 6.6.72, 6.12.10, 6.13 | Patch available | CNA |
- Linux VendorLinux Affected 4.7 and later Fixed in 5.10.234, 5.15.177, 6.1.125, 6.6.72, 6.12.10, 6.13 Patch available CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.7.1 to before 5.10.234; 5.11 to before 5.15.177; 5.16 to before 6.1.125; 6.2 to before 6.6.72; 6.7 to before 6.12.10 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.7:-:*:*:*:*:*:* | 4.7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* | 6.13 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* | 6.13 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* | 6.13 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* | 6.13 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* | 6.13 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:* | 6.13 rc6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.7.1 to before 5.10.234; 5.11 to before 5.15.177; 5.16 to before 6.1.125; 6.2 to before 6.6.72; 6.7 to before 6.12.10 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.7:-:*:*:*:*:*:* Versions 4.7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* Versions 6.13 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* Versions 6.13 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* Versions 6.13 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* Versions 6.13 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* Versions 6.13 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:* Versions 6.13 rc6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.234, 5.15.177, 6.1.125, 6.6.72, 6.12.10, 6.13
Red Hat 2 advisories
- RHSA-2026:34094 Released 2026-07-01 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder EUS (v.9.6) kernel-tools-libs-devel-5.14.0-570.125.1.el9_6, libperf-5.14.0-570.125.1.el9_6
- Red Hat Enterprise Linux AppStream EUS (v.9.6) kernel-64k-debug-devel-5.14.0-570.125.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.125.1.el9_6, kernel-64k-devel-5.14.0-570.125.1.el9_6 +12
- Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel-5.14.0-570.125.1.el9_6, kernel-64k-5.14.0-570.125.1.el9_6, kernel-64k-core-5.14.0-570.125.1.el9_6 +28
- Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt-5.14.0-570.125.1.el9_6, kernel-rt-64k-5.14.0-570.125.1.el9_6, kernel-rt-64k-core-5.14.0-570.125.1.el9_6 +21
- Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt-5.14.0-570.125.1.el9_6, kernel-rt-core-5.14.0-570.125.1.el9_6, kernel-rt-debug-5.14.0-570.125.1.el9_6 +11
- RHSA-2025:20518 Released 2025-11-11 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-611.5.1.el9_7, kernel-64k-debug-devel-matched-5.14.0-611.5.1.el9_7, kernel-64k-devel-5.14.0-611.5.1.el9_7 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-611.5.1.el9_7, kernel-64k-5.14.0-611.5.1.el9_7, kernel-64k-core-5.14.0-611.5.1.el9_7 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-611.5.1.el9_7, libperf-5.14.0-611.5.1.el9_7
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-611.5.1.el9_7, kernel-rt-64k-5.14.0-611.5.1.el9_7, kernel-rt-64k-core-5.14.0-611.5.1.el9_7 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-611.5.1.el9_7, kernel-rt-core-5.14.0-611.5.1.el9_7, kernel-rt-debug-5.14.0-611.5.1.el9_7 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat CodeReady Linux Builder EUS (v.9.6) | Fixed | RHSA-2026:34094 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:34094 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.6) | Fixed | RHSA-2026:34094 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux Real Time EUS (v.9.6) | Fixed | RHSA-2026:34094 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) | Fixed | RHSA-2026:34094 |
Not affected: 1 product
- Red Hat Enterprise Linux 10
Timeline
- 2026-10-02 Threatist record created from CVE-2025-21648
- 2026-10-03 Alias added: GHSA-w9f5-vpqq-grqj
References
Patch 6
- https://git.kernel.org/stable/c/a965f7f0ea3ae61b9165bed619d5d6da02c75f80
- https://git.kernel.org/stable/c/b1b2353d768f1b80cd7fe045a70adee576b9b338
- https://git.kernel.org/stable/c/5552b4fd44be3393b930434a7845d8d95a2a3c33
- https://git.kernel.org/stable/c/d5807dd1328bbc86e059c5de80d1bbee9d58ca3d
- https://git.kernel.org/stable/c/f559357d035877b9d0dcd273e0ff83e18e1d46aa
- https://git.kernel.org/stable/c/b541ba7d1f5a5b7b3e2e22dc9e40e18a7d6dbc13
More Linux Kernel vulnerabilities
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- 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-2025-21648 · CVE Program
- CVE-2025-21648 · NVD
- FIRST EPSS
- GHSA-w9f5-vpqq-grqj · GitHub Advisory Database · CC BY 4.0
- CVE-2025-21648 · Red Hat security data · CC BY 4.0
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