Cyber Resilience

CVE-2025-21648

Linux Kernel 4.7.1 – 5.10.234

Published
19 January 2025
Modified
14 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0022 12th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-21648 is a medium-severity an unspecified weakness vulnerability in Linux Linux Kernel. Its CVSS base score is 5.5 (Medium).

Operationally, ranked at the 12th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and CM-6 (Configuration Settings) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

__GFP_NOWARN is unset. See: 0708a0afe291 ("mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls") Note: hashtable resize is only possible from init_netns.

CWE(s)
NVD-CWE-Other

Related Threats

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Affected Assets

linux
linux kernel
4.7, 6.13 · 4.7.1 — 5.10.234 · 5.11 — 5.15.177 · 5.16 — 6.1.125

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SC-6 Resource Availability
  • CM-6 Configuration Settings
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly enforces bounds checking on the conntrack hashtable size parameter supplied to kvmalloc, preventing the oversized allocation that triggers the WARN_ON_ONCE.

SC-6 Resource Availability partial match
prevent

Limits the impact of an unbounded allocation request by protecting availability of kernel memory resources during hashtable resize from init_netns.

CM-6 Configuration Settings partial match
prevent

Requires explicit configuration settings that clamp the conntrack hashtable maximum size to INT_MAX, eliminating the unsafe default behavior.

References