PT-2026-61145 · Linux · Linux Kernel

CVE-2026-63829 · Published 2026-07-19 · Updated 2026-07-20

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the ip gre component where the changelink() operation does not properly verify the CAP NET ADMIN capability within the tunnel link network namespace (t->net). Because the system only checks for this capability against the device network namespace (dev net(dev)), a user with privileges in the device namespace but lacking them in the link namespace can modify a tunnel residing in the link namespace. This occurs during the RTM NEWLINK path, specifically affecting the ipgre changelink() and erspan changelink() functions.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2026-63829

Affected Products

Linux Kernel

References · 7

• https://nvd.nist.gov/vuln/detail/CVE-2026-63829 · Security Note
• https://twitter.com/VulmonFeeds/status/2078853612445356239 · Twitter Post
• https://git.kernel.org/stable/c/9831bc9ecb402957810c2045c663fbfe9b09e296 · Note
• https://git.kernel.org/stable/c/47b5d3d506609b08b2e1f7c14f0b681a1953d572 · Note
• https://git.kernel.org/stable/c/1697957eb0971d420dde42862b88eb43506a1105 · Note
• https://git.kernel.org/stable/c/8165f7ff57d9667d2bb477ef6af83ede7fed4ad7 · Note
• https://twitter.com/windowsforum/status/2079104554495336502 · Twitter Post