netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state (CVE-2026-93288) | HOL Guard CVE

High · CVSS 7.8CVE-2026-93288

netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state

Answer in brief

CVE-2026-93288 records a High severity (CVSS 7.8) vulnerability in netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 24, 2026Updated Sep 25, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 25, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f4461654374576e9d5d0245fd534c46ad8509051 \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <dc20050b6b12ca58066715d088e1a537535d938d \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <33d1469b0124cc0baaea7a2032123b77a81e0940 \|\| >=0 <6.12.111 \|\| >=0 <6.18.53	f4461654374576e9d5d0245fd534c46ad8509051, dc20050b6b12ca58066715d088e1a537535d938d, 33d1469b0124cc0baaea7a2032123b77a81e0940, 6.12.111, 6.18.53

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux.
Review the reported fix. Update Linux/Linux to f4461654374576e9d5d0245fd534c46ad8509051 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state sashiko reports: "nfnl_log_net_exit() calls nf_log_unset(), which clears the logger pointer without an RCU grace period. Immediately after, ops_free_list() frees the per-net state while concurrent packets might still be executing nf_log_packet() under rcu_read_lock()." Clear the pointer via .pre_exit to make sure rcu readers have completed before pernet storage is free'd. The change in nf_log_syslog.c is only done for consistency: it doesn't use pernet data.

Quoted source text, attributed separately from HOL analysis.