Skip to main content
VulnerabilityPublished Updated

CVE-2026-63829: Linux kernel · Missing Authorization

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High · fixed in e54c05ed3d9c28733fb9e5837219aca3691defa3 : patch Linux kernel soon.

Data as of 26 Oct 2026, 16:39 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in e54c05ed3d9c28733fb9e5837219aca3691defa3, 19275943d8fe903eb7b9aa53e380e41efd042ada, 1697957eb0971d420dde42862b88eb43506a1105 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ b57708add31494175be741ed3fd24023b50c3423, < e54c05ed3d9c28733fb9e5837219aca3691defa3
Fixed in
  • e54c05ed3d9c28733fb9e5837219aca3691defa3
LinuxLinuxAffected
  • ≥ b57708add31494175be741ed3fd24023b50c3423, < 19275943d8fe903eb7b9aa53e380e41efd042ada
Fixed in
  • 19275943d8fe903eb7b9aa53e380e41efd042ada
LinuxLinuxAffected
  • ≥ b57708add31494175be741ed3fd24023b50c3423, < 1697957eb0971d420dde42862b88eb43506a1105
Fixed in
  • 1697957eb0971d420dde42862b88eb43506a1105
LinuxLinuxAffected
  • ≥ b57708add31494175be741ed3fd24023b50c3423, < 9831bc9ecb402957810c2045c663fbfe9b09e296
Fixed in
  • 9831bc9ecb402957810c2045c663fbfe9b09e296
LinuxLinuxAffected
  • ≥ b57708add31494175be741ed3fd24023b50c3423, < 8165f7ff57d9667d2bb477ef6af83ede7fed4ad7
Fixed in
  • 8165f7ff57d9667d2bb477ef6af83ede7fed4ad7
LinuxLinuxAffected
  • ≥ b57708add31494175be741ed3fd24023b50c3423, < 866b0f5ae599490bd496fd84581c68ac8b94e6af
Fixed in
  • 866b0f5ae599490bd496fd84581c68ac8b94e6af

Description

In the Linux kernel, the following vulnerability has been resolved: net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink A tunnel 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. Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is skipped when the link netns is dev_net(dev), where the rtnl path already checked it. The other patches in this series use the same helper. Gate ipgre_changelink() and erspan_changelink() with it, at the top of the op before any attribute is parsed, because the parsers update live tunnel fields first. ipgre_netlink_parms() sets t->collect_md before ip_tunnel_changelink() runs. Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().") added the same check on the ioctl path. This adds it on RTM_NEWLINK.

References

Community reviews

Loading reviews…