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

Vulnerability from cvelistv5 – Published: 2026-08-15 05:52 – Updated: 2026-08-23 12:46
VLAI
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
References
Impacted products
Vendor Product Version CPE status
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)
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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)
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          "product": "Linux",
          "programFiles": [
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                  "versionEndExcluding": "5.10.266",
                  "versionStartIncluding": "3.12",
                  "vulnerable": true
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              "negate": false,
              "operator": "OR"
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      "descriptions": [
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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."
        }
      ],
      "metrics": [
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            "version": "3.1"
          },
          "scenarios": [
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              "lang": "en",
              "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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    "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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      "date": "2026-09-04",
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      "percentile": "0.0642"
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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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/ipv6/ip6_tunnel.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"0bd8762824e73a3cce7b7560a97463301764b616\",\"lessThan\":\"2d53ee7daabe733deb81f51d2cc90188f8ad59a1\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0bd8762824e73a3cce7b7560a97463301764b616\",\"lessThan\":\"82e53e7281c71e174f9f5877c566a623c637b406\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0bd8762824e73a3cce7b7560a97463301764b616\",\"lessThan\":\"5252db8fb604321133138c7069d6fc3fcd89cdee\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0bd8762824e73a3cce7b7560a97463301764b616\",\"lessThan\":\"2636d061bc237a2446a146e42dcc6563acfa7432\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0bd8762824e73a3cce7b7560a97463301764b616\",\"lessThan\":\"7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0bd8762824e73a3cce7b7560a97463301764b616\",\"lessThan\":\"234cd54fc500f69db43e37de38603da617fbbeea\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0bd8762824e73a3cce7b7560a97463301764b616\",\"lessThan\":\"d4bcc202a3530c856e1cb183384bc9cc8fddab22\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0bd8762824e73a3cce7b7560a97463301764b616\",\"lessThan\":\"2496fa0b7d180b3ad356b514e7ff93bb14e6140a\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/ipv6/ip6_tunnel.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.12\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.12\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.266\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.217\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.184\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.148\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.101\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.40\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.0,\"impactScore\":6.0}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/234cd54fc500f69db43e37de38603da617fbbeea\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2496fa0b7d180b3ad356b514e7ff93bb14e6140a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2636d061bc237a2446a146e42dcc6563acfa7432\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2d53ee7daabe733deb81f51d2cc90188f8ad59a1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/5252db8fb604321133138c7069d6fc3fcd89cdee\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/82e53e7281c71e174f9f5877c566a623c637b406\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d4bcc202a3530c856e1cb183384bc9cc8fddab22\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-17T18:54:36+00:00",
      "cve": "CVE-2026-72051",
      "id": "CVE-2026-72051",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72051.json",
      "version": "3"
    }
  }
}



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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.

Sightings

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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.


Detection rules are retrieved from Rulezet.