CVE-2026-53219

netfilter: x_tables: avoid leaking percpu counter pointers

MEDIUM
5.5
CVSS Score
Published: June 25, 2026 at 08:39 AM UTC
Updated: October 15, 2026 at 02:20 AM UTC
4 products affected across 2 vendorsLinux KernelSIMATIC S7-1500 CPU 1518-4 Pn /dp MFP FirmwareSiplus S7-1500 CPU 1518-4 Pn /dp MFP Firmware

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: x_tables: avoid leaking percpu counter pointers The native and compat get-entries paths copy the fixed rule entry header from the kernelized rule blob to userspace before overwriting the entry's counter fields with a sanitized counter snapshot. On SMP kernels, entry->counters.pcnt contains the percpu allocation address used by x_tables rule counters. A caller can provide a userspace buffer that faults during the initial fixed-header copy after pcnt has been copied but before the later sanitized counter copy runs. The syscall then returns -EFAULT while leaving the raw percpu pointer in userspace. Copy only the fixed entry prefix before counters from the kernelized rule blob, then copy the sanitized counter snapshot into the counter field. Apply this ordering to the IPv4, IPv6, and ARP native and compat get-entries implementations so a fault cannot expose the internal percpu counter pointer.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.2 ≤ v < 5.10.2595.11 ≤ v < 5.15.2105.16 ≤ v < 6.1.1766.13 ≤ v < 6.18.366.19 ≤ v < 7.0.136.2 ≤ v < 6.6.1436.7 ≤ v < 6.12.947.17.1 rc17.1 rc27.1 rc37.1 rc47.1 rc57.1 rc67.1 rc771ae0dff02d756e4d2ca710b79f2ff5390029a5f
Vendor states this is fixed in 08a3e218064db11f154ad9ad5541751ea7f34ebe (fixed)
Vendor states this is fixed in 0b35dc8527ccc16b7dc34e8a3164313e68cd4e45 (fixed)
Vendor states this is fixed in 8d67e42ad3b1a95a152541015a07110e06992d6c (fixed)
Vendor states this is fixed in a0d16941adf3a501956d74aefd8d6e217906e79c (fixed)
Vendor states this is fixed in b28e2fcad3db7e8687b15bc20bced26b5b7c920e (fixed)
Vendor states this is fixed in b74ba3343eb44b2cbf7e9665918c287df1d52ebb (fixed)
Vendor states this is fixed in f7f2fbb0e893a0238dc464f8d8c0f5609bec584f (fixed)
Vendor states this is fixed in fb0521aff1e10e300d89725cc439d3ea74c828c5 (fixed)
Vendor states this is fixed in 4.2 (unaffected)
Vendor states this is fixed in 5.10.259 (unaffected)
Vendor states this is fixed in 5.15.210 (unaffected)
Vendor states this is fixed in 6.1.176 (unaffected)
Vendor states this is fixed in 6.12.94 (unaffected)
Vendor states this is fixed in 6.18.36 (unaffected)
Vendor states this is fixed in 6.6.143 (unaffected)
Vendor states this is fixed in 7.0.13 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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