netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref() (CVE-2026-74695) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-74695

netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref()

Answer in brief

CVE-2026-74695 records a Unknown severity vulnerability in netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), 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 Aug 22, 2026Updated Aug 22, 2026Source checked Aug 22, 2026First seen by HOL Aug 22, 2026Material review Aug 22, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. 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), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=2a79fd3908acd88e6cb0e620c314d7b1fee56a02 <12afa450a6a6c0cce2c42b7545a9958f62d8a00c \|\| >=2a79fd3908acd88e6cb0e620c314d7b1fee56a02 <538e67e8c7889cf5f93951f5309d1bcb41f86036 \|\| >=2a79fd3908acd88e6cb0e620c314d7b1fee56a02 <8aecf0bbcc72605592134c917c222207d8f63ab0 \|\| b4b1adf2e66ecc7125c4117e7aad9ff61e2cfd27 \|\| 209dedf806d31095968f54323dbe62525b077b33 \|\| >=4.16.15 <4.17 \|\| >=4.17.1 <4.18	12afa450a6a6c0cce2c42b7545a9958f62d8a00c, 538e67e8c7889cf5f93951f5309d1bcb41f86036, 8aecf0bbcc72605592134c917c222207d8f63ab0, 4.17, 4.18
Linux/Linuxgeneric	4.18	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 12afa450a6a6c0cce2c42b7545a9958f62d8a00c if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 22, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref() Incoming skbs passing through netfilter flowtable offload hooks (or XFRM offload path) might already carry a ref-counted dst_entry assigned during earlier RX or routing steps. Calling skb_dst_set_noref() when skb already holds a ref-counted dst overwrites skb->_skb_refdst, leaking the previous dst_entry reference count and triggering a DEBUG_NET_WARN_ON_ONCE assertion in skb_dst_check_unset(): WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170 WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234 WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864 Drop any existing dst_entry reference with skb_dst_drop(skb) before setting the non-referenced flowtable destination.

Quoted source text, attributed separately from HOL analysis.