vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive(). (CVE-2026-74406) | HOL Guard CVE

Critical · CVSS 9.8CVE-2026-74406

vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive().

Answer in brief

CVE-2026-74406 records a Critical severity (CVSS 9.8) vulnerability in vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive().. 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 15, 2026Updated Aug 17, 2026Source checked Sep 29, 2026First seen by HOL Aug 15, 2026Material review Aug 17, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.8
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 9.8. 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), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=5602c48cf87562c2f95b831d690631935e834295 <9c58c729d32e7cea5772cc44929c6cd61e5a31cd \|\| >=5602c48cf87562c2f95b831d690631935e834295 <f79c80f173fda9545b220c1f094b65fc06c252d0 \|\| >=5602c48cf87562c2f95b831d690631935e834295 <08f40c0d23c67c3aa4224c3311e134999c721fb4 \|\| >=5602c48cf87562c2f95b831d690631935e834295 <4a8cde6f7281ea2c4c290f9ad9923b3631defceb \|\| >=5602c48cf87562c2f95b831d690631935e834295 <ef44dac2a37f86eeae6b88ed10a6d60b35387dfd \|\| >=5602c48cf87562c2f95b831d690631935e834295 <30a45c0bffdd62350261e2f2689fdba426a33578	9c58c729d32e7cea5772cc44929c6cd61e5a31cd, f79c80f173fda9545b220c1f094b65fc06c252d0, 08f40c0d23c67c3aa4224c3311e134999c721fb4, 4a8cde6f7281ea2c4c290f9ad9923b3631defceb, ef44dac2a37f86eeae6b88ed10a6d60b35387dfd, 30a45c0bffdd62350261e2f2689fdba426a33578
Linux/Linuxgeneric	4.7	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 9c58c729d32e7cea5772cc44929c6cd61e5a31cd if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 15, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive(). udp_tunnel_sock_release() could set sk->sk_user_data to NULL while vxlan_gro_prepare_receive() is running. Let's check if rcu_dereference_sk_user_data() is NULL after skb_gro_remcsum_init().

Quoted source text, attributed separately from HOL analysis.