CVE-2026-72463 (GCVE-0-2026-72463)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:57 – Updated: 2026-08-17 05:44
VLAI
Title
xfrm: Fix dev use-after-free in xfrm async resumption
Summary
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.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 1c428b03840094410c5fb6a5db30640486bbbfcb , < 63a30015199912bd5055bead8001b1ae68a67cdb (git)
Affected: 1c428b03840094410c5fb6a5db30640486bbbfcb , < 8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff (git)
Affected: 4236c30b437b80f673b9e08c8fae38b8d471ac9e (git)
Affected: 0f451b43c88bf2b9c038b414be580efee42e031b (git)
Affected: 5002beda5cac69d522dc54da0d5d463ed9c963d2 (git)
Affected: 6.12.94 , < 6.13 (semver)
Affected: 6.18.23 , < 6.19 (semver)
Affected: 6.19.13 , < 6.20 (semver)
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Linux Linux Affected: 7.0
Unaffected: 0 , < 7.0 (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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          "product": "Linux",
          "programFiles": [
            "net/ipv4/xfrm4_input.c",
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: Fix dev use-after-free in xfrm async resumption\n\nxfrm async resumption hold skb-\u003edev refcnt until after transport_finish.\nHowever, xfrm_rcv_cb may modify skb-\u003edev to tunnel dev without taking\ndevice reference, such as vti_rcv_cb. The subsequent async resumption\nwill decrement the tunnel device\u0027s reference count, which lead to uaf\nof tunnel dev and refcnt leak of orig dev as below:\n\nunregister_netdevice: waiting for vti1 to become free. Usage count = -2\n\nStash the original skb-\u003edev to fix refcnt imbalance. The new skb-\u003edev set\nby xfrm_rcv_cb can race with device teardown. Extend rcu protection over\nxfrm_rcv_cb and transport_finish to prevent races."
        }
      ],
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          },
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              "value": "AV:N - Reachable from the network receive path: remote ESP/AH (or UDP-encapsulated IPsec) packets hit ip_rcv \u2192 xfrm4/xfrm6 protocol handlers \u2192 vti/xfrmi input \u2192 xfrm_input() \u2192 async crypto resume, on Internet-facing IPsec/VTI/xfrmi VPN gateways and cloud endpoints.\nAC:L - Once async decryption resumes (encap_type=-1), vti_rcv_cb/xfrmi_rcv_cb retarget skb-\u003edev and the stale dev_put is deterministic; the attacker controls packet rate/volume to drive -EINPROGRESS and can race netdev teardown, so no uncontrollable victim-only conditions apply.\nPR:N - No local account, shell, or capability on the victim is required\u2014only network-delivered IPsec traffic accepted by a pre-configured VTI/xfrmi gateway (e.g., VPN peer, site-to-site endpoint); administrative IPsec setup is deployment state, not attacker privilege on the host.\nUI:N - Exploitation is fully automated by sending IPsec packets; no victim interaction such as mounting filesystems, opening files, or clicking links is needed.\nS:U - Impact is kernel net_device refcount corruption/UAF within the host kernel security authority; it does not cross VM, IOMMU, or sandbox boundaries (standard kernel privilege escalation, not escape).\nC:H - Use-after-free of a net_device after refcount underflow (e.g., usage count=-2) exposes freed netdev/slab memory; per kernel UAF guidance this provides a high-impact arbitrary-read primitive via heap grooming.\nI:H - Corrupting freed net_device structures and reference counts is classic heap UAF that can be shaped into arbitrary kernel writes and control-flow hijack for code execution, per kernel memory-corruption guidance.\nA:H - Refcount imbalance causes unregister_netdevice to hang (usage count=-2), kernel oops/panic during tunnel teardown, and reliable denial of service on IPsec gateways even before full exploitation."
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:44:29.613Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/63a30015199912bd5055bead8001b1ae68a67cdb"
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        {
          "url": "https://git.kernel.org/stable/c/8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff"
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      "title": "xfrm: Fix dev use-after-free in xfrm async resumption",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72463",
    "datePublished": "2026-08-15T05:57:07.413Z",
    "dateReserved": "2026-08-09T03:40:39.933Z",
    "dateUpdated": "2026-08-17T05:44:29.613Z",
    "state": "PUBLISHED"
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  "vulnerability-lookup:meta": {
    "epss": {
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  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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