{"id":"CVE-2026-63829","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ip_gre: require CAP_NET_ADMIN in the device netns for changelink\n\nA tunnel changelink() operates on at most two netns, dev_net(dev) and\nthe tunnel link netns t->ne…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ip_gre: require CAP_NET_ADMIN in the device netns for changelink\n\nA tunnel changelink() operates on at most two netns, dev_net(dev) and\nthe tunnel link netns t->ne…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","published":"2026-07-19","updated":"2026-08-17","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63829","references":[{"url":"https://git.kernel.org/stable/c/1697957eb0971d420dde42862b88eb43506a1105","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/19275943d8fe903eb7b9aa53e380e41efd042ada","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/47b5d3d506609b08b2e1f7c14f0b681a1953d572","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8165f7ff57d9667d2bb477ef6af83ede7fed4ad7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/866b0f5ae599490bd496fd84581c68ac8b94e6af","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/92b766fc55156e0da2ecd0c2302c971118f8a229","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9831bc9ecb402957810c2045c663fbfe9b09e296","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e54c05ed3d9c28733fb9e5837219aca3691defa3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63829.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-63829"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2502230"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63829"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63829"},{"url":"https://lore.kernel.org/linux-cve-announce/2026071908-CVE-2026-63829-ff2a@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2026:76738"},{"url":"https://access.redhat.com/errata/RHSA-2026:76739"},{"url":"https://access.redhat.com/errata/RHSA-2026:75747"},{"url":"https://access.redhat.com/errata/RHSA-2026:75746"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00148,"epssPercentile":0.03926,"ingestedAt":"2026-08-17T05:47:50.343Z","vendor":"Linux","product":"Linux","affected":["Linux >= b57708add31494175be741ed3fd24023b50c3423 < 19275943d8fe903eb7b9aa53e380e41efd042ada","Linux >= b57708add31494175be741ed3fd24023b50c3423 < 866b0f5ae599490bd496fd84581c68ac8b94e6af","Linux >= b57708add31494175be741ed3fd24023b50c3423 < 92b766fc55156e0da2ecd0c2302c971118f8a229","Linux >= b57708add31494175be741ed3fd24023b50c3423 < e54c05ed3d9c28733fb9e5837219aca3691defa3","Linux >= b57708add31494175be741ed3fd24023b50c3423 < 9831bc9ecb402957810c2045c663fbfe9b09e296","Linux >= b57708add31494175be741ed3fd24023b50c3423 < 1697957eb0971d420dde42862b88eb43506a1105","Linux >= b57708add31494175be741ed3fd24023b50c3423 < 47b5d3d506609b08b2e1f7c14f0b681a1953d572","Linux >= b57708add31494175be741ed3fd24023b50c3423 < 8165f7ff57d9667d2bb477ef6af83ede7fed4ad7","Linux 3.16"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:31:15.242549Z"},"patched":["10base_smtv","enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_8","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_v_10","enterprise_linux_crb_v_8","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_hidden_v_10","enterprise_linux_real_time_for_nfv_v_10","enterprise_linux_nfv_v_8","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_10","enterprise_linux_rt_v_8","enterprise_linux_real_time_v_9"],"cwe":["CWE-266"],"scores":{"nvd":8.8,"vendor":7.8},"slug":"CVE-2026-63829","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: ip_gre: require CAP_NET_ADMIN in the device netns for changelink\n\nA tunnel changelink() operates on at most two netns, dev_net(dev) and\nthe tunnel link netns t->net. They differ once the device is created in\nor moved 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->net can rewrite a tunnel that\nlives in t->net.\n\nAdd rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in\nnet/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is\nskipped when the link netns is dev_net(dev), where the rtnl path already\nchecked it. The other patches in this series use the same helper.\n\nGate ipgre_changelink() and erspan_changelink() with it, at the top of\nthe op before any attribute is parsed, because the parsers update live\ntunnel fields first. ipgre_netlink_parms() sets t->collect_md before\nip_tunnel_changelink() runs.\n\nCommit 8b484efd5cb4 (\"ip6: vti: Use ip6_tnl.net in\nvti6_siocdevprivate().\") added the same check on the ioctl path. This\nadds it on RTM_NEWLINK.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:76738** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:76738)\n- **RHSA-2026:76739** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:76739)\n- **RHSA-2026:75747** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-05 · [advisory](https://access.redhat.com/errata/RHSA-2026:75747)\n- **RHSA-2026:75746** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-10-05 · [advisory](https://access.redhat.com/errata/RHSA-2026:75746)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 7 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63829.json)","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}