Vulnerability-Lookup

GHSA-Q3JR-W6WF-464W

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-23 15:32

Details

In the Linux kernel, the following vulnerability has been resolved:

net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink

ip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net.

Gate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top, before any attribute is parsed.

Severity

8.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-72051"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:21:14Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink\n\nip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the\ntunnel link netns t-\u003enet. They differ once the device is created in or\nmoved to a netns other than the one the request runs in. The rtnl\nchangelink path checks CAP_NET_ADMIN only against dev_net(dev), so a\ncaller privileged there but not in t-\u003enet can rewrite a tunnel that\nlives in t-\u003enet.\n\nGate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top,\nbefore any attribute is parsed.",
  "id": "GHSA-q3jr-w6wf-464w",
  "modified": "2026-08-23T15:32:58Z",
  "published": "2026-08-15T06:32:10Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72051"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/234cd54fc500f69db43e37de38603da617fbbeea"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2496fa0b7d180b3ad356b514e7ff93bb14e6140a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2636d061bc237a2446a146e42dcc6563acfa7432"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2d53ee7daabe733deb81f51d2cc90188f8ad59a1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5252db8fb604321133138c7069d6fc3fcd89cdee"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/82e53e7281c71e174f9f5877c566a623c637b406"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d4bcc202a3530c856e1cb183384bc9cc8fddab22"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-72051 (GCVE-0-2026-72051)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:52 – Updated: 2026-08-23 12:46

Title

net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink

Summary

In the Linux kernel, the following vulnerability has been resolved: net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink ip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Gate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top, before any attribute is parsed.

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Assigner

Linux mitre root Scorecard

References

8 references

URL	Tags
https://git.kernel.org/stable/c/2d53ee7daabe733de…
https://git.kernel.org/stable/c/82e53e7281c71e174…
https://git.kernel.org/stable/c/5252db8fb60432113…
https://git.kernel.org/stable/c/2636d061bc237a244…
https://git.kernel.org/stable/c/7f68f7928484f463a…
https://git.kernel.org/stable/c/234cd54fc500f69db…
https://git.kernel.org/stable/c/d4bcc202a3530c856…
https://git.kernel.org/stable/c/2496fa0b7d180b3ad…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 0bd8762824e73a3cce7b7560a97463301764b616 , < 2d53ee7daabe733deb81f51d2cc90188f8ad59a1 (git) Affected: 0bd8762824e73a3cce7b7560a97463301764b616 , < 82e53e7281c71e174f9f5877c566a623c637b406 (git) Affected: 0bd8762824e73a3cce7b7560a97463301764b616 , < 5252db8fb604321133138c7069d6fc3fcd89cdee (git) Affected: 0bd8762824e73a3cce7b7560a97463301764b616 , < 2636d061bc237a2446a146e42dcc6563acfa7432 (git) Affected: 0bd8762824e73a3cce7b7560a97463301764b616 , < 7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa (git) Affected: 0bd8762824e73a3cce7b7560a97463301764b616 , < 234cd54fc500f69db43e37de38603da617fbbeea (git) Affected: 0bd8762824e73a3cce7b7560a97463301764b616 , < d4bcc202a3530c856e1cb183384bc9cc8fddab22 (git) Affected: 0bd8762824e73a3cce7b7560a97463301764b616 , < 2496fa0b7d180b3ad356b514e7ff93bb14e6140a (git)
Linux	Linux	Affected: 3.12 Unaffected: 0 , < 3.12 (semver) Unaffected: 5.10.266 , ≤ 5.10.* (semver) Unaffected: 5.15.217 , ≤ 5.15.* (semver) Unaffected: 6.1.184 , ≤ 6.1.* (semver) Unaffected: 6.6.148 , ≤ 6.6.* (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/ip6_tunnel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "82e53e7281c71e174f9f5877c566a623c637b406",
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              "version": "0bd8762824e73a3cce7b7560a97463301764b616",
              "versionType": "git"
            },
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              "lessThan": "5252db8fb604321133138c7069d6fc3fcd89cdee",
              "status": "affected",
              "version": "0bd8762824e73a3cce7b7560a97463301764b616",
              "versionType": "git"
            },
            {
              "lessThan": "2636d061bc237a2446a146e42dcc6563acfa7432",
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              "version": "0bd8762824e73a3cce7b7560a97463301764b616",
              "versionType": "git"
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              "versionType": "git"
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              "versionType": "git"
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            {
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              "status": "affected",
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.12"
            },
            {
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.266",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.217",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.184",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
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              "versionType": "semver"
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              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
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            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
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          "nodes": [
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink\n\nip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the\ntunnel link netns t-\u003enet. They differ once the device is created in or\nmoved to a netns other than the one the request runs in. The rtnl\nchangelink path checks CAP_NET_ADMIN only against dev_net(dev), so a\ncaller privileged there but not in t-\u003enet can rewrite a tunnel that\nlives in t-\u003enet.\n\nGate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top,\nbefore any attribute is parsed."
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            "version": "3.1"
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              "value": "AV:L - Exploitation requires RTM_NEWLINK changelink over a local rtnetlink socket; ip6_tnl_changelink is only reachable from rtnl configuration, not from received IPv6 packets processed by ip6_tnl_rcv.\nAC:L - Once an ip6tnl device exists with t-\u003enet differing from dev_net(dev) (IFLA_LINK_NETNSID newlink or IFLA_NET_NS_FD migration), a single deterministic netlink changelink bypasses the missing check with no race or memory-layout dependency.\nPR:L - The rtnl entry path requires CAP_NET_ADMIN only in dev_net(dev), obtainable by an unprivileged local user via unshare --user --map-root-user --net; no CAP_NET_ADMIN in the sticky link netns t-\u003enet is required.\nUI:N - The attack is fully programmatic through netlink from the attacker\u0027s own process; no victim action such as mounting a filesystem, opening a file, or clicking is required.\nS:C - Authorization is checked against dev_net(dev) while ip6_tnl_changelink mutates tunnel state in t-\u003enet via ip6_tnl_update, crossing from the attacker\u0027s net/user namespace into another tenant\u0027s or the host\u0027s network namespace.\nC:H - An attacker can rewrite IFLA_IPTUN_LOCAL/REMOTE, link, fwmark, and encap parameters to redirect IPv6/IPv4-over-IPv6 tunnel traffic to an attacker-controlled endpoint and read all tunneled payloads in the victim link netns.\nI:H - Unauthorized changelink updates live tunnel endpoints, underlay link, encap ports, and flowinfo/fwmark in t-\u003enet, enabling redirection and injection of traffic carried over the ip6tnl tunnel.\nA:H - Rewriting tunnel remote/local addresses, underlay device, or encap parameters breaks cross-netns IPv6 tunnel connectivity, causing sustained loss of service for every workload depending on the affected ip6tnl tunnel."
            }
          ]
        }
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        "dateUpdated": "2026-08-23T12:46:34.252Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        },
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          "url": "https://git.kernel.org/stable/c/2496fa0b7d180b3ad356b514e7ff93bb14e6140a"
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      "title": "net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72051",
    "datePublished": "2026-08-15T05:52:08.445Z",
    "dateReserved": "2026-08-09T03:40:39.902Z",
    "dateUpdated": "2026-08-23T12:46:34.252Z",
    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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GHSA-Q3JR-W6WF-464W

CVE-2026-72051 (GCVE-0-2026-72051)

Tags

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Nomenclature

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