xfrm: Fix dev use-after-free in xfrm async resumption (CVE-2026-72463) | HOL Guard CVE

Critical · CVSS 9.8CVE-2026-72463

xfrm: Fix dev use-after-free in xfrm async resumption

Answer in brief

CVE-2026-72463 records a Critical severity (CVSS 9.8) vulnerability in xfrm: Fix dev use-after-free in xfrm async resumption. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), 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 Sep 25, 2026Source checked Sep 29, 2026First seen by HOL Aug 15, 2026Material review Sep 25, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.8
Exploitation: Not marked as known exploited
Affected software: 3 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), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=1c428b03840094410c5fb6a5db30640486bbbfcb <63a30015199912bd5055bead8001b1ae68a67cdb \|\| >=1c428b03840094410c5fb6a5db30640486bbbfcb <8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff \|\| 4236c30b437b80f673b9e08c8fae38b8d471ac9e \|\| 0f451b43c88bf2b9c038b414be580efee42e031b \|\| 5002beda5cac69d522dc54da0d5d463ed9c963d2 \|\| >=6.12.94 <6.13 \|\| >=6.18.23 <6.19 \|\| >=6.19.13 <6.20	63a30015199912bd5055bead8001b1ae68a67cdb, 8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff, 6.13, 6.19, 6.20
Linux/Linuxgeneric	7.0	Not reported
Linux/Linuxgeneric	>=0f451b43c88bf2b9c038b414be580efee42e031b <1acd93259b6be269e26be5d71c224bccd1f8352f \|\| >=1c428b03840094410c5fb6a5db30640486bbbfcb <63a30015199912bd5055bead8001b1ae68a67cdb \|\| >=1c428b03840094410c5fb6a5db30640486bbbfcb <8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff \|\| 4236c30b437b80f673b9e08c8fae38b8d471ac9e \|\| 5002beda5cac69d522dc54da0d5d463ed9c963d2 \|\| >=6.18.23 <6.18.54 \|\| >=6.12.94 <6.13 \|\| >=6.19.13 <6.20	1acd93259b6be269e26be5d71c224bccd1f8352f, 63a30015199912bd5055bead8001b1ae68a67cdb, 8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff, 6.18.54, 6.13, 6.20

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 63a30015199912bd5055bead8001b1ae68a67cdb; Linux/Linux to 1acd93259b6be269e26be5d71c224bccd1f8352f 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
Sep 25, 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: xfrm: Fix dev use-after-free in xfrm async resumption xfrm async resumption hold skb->dev refcnt until after transport_finish. However, xfrm_rcv_cb may modify skb->dev to tunnel dev without taking device reference, such as vti_rcv_cb. The subsequent async resumption will decrement the tunnel device's reference count, which lead to uaf of tunnel dev and refcnt leak of orig dev as below: unregister_netdevice: waiting for vti1 to become free. Usage count = -2 Stash the original skb->dev to fix refcnt imbalance. The new skb->dev set by xfrm_rcv_cb can race with device teardown. Extend rcu protection over xfrm_rcv_cb and transport_finish to prevent races.

Quoted source text, attributed separately from HOL analysis.