PT-2026-61139 · Linux · Linux Kernel

CVE-2026-63823 · Published 2026-07-19 · Updated 2026-07-19

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

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

Description A use-after-free issue exists in the Linux kernel during the handling of request key auth payloads. The problem occurs during a concurrency scenario involving the request key() function and the KEYCTL INSTANTIATE IOV operation. Specifically, a race condition can occur where a helper completes and frees the request key auth (rka) payload and destroys the authentication key while another process is still attempting to use rka->target key after waking up from a page fault (#PF), leading to memory corruption.

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

Related Identifiers

CVE-2026-63823

Affected Products

Linux Kernel

References · 10

• https://nvd.nist.gov/vuln/detail/CVE-2026-63823 · Security Note
• https://git.kernel.org/stable/c/35ab4db86774d82389e4b9559e26ab7f68d8e395 · Note
• https://git.kernel.org/stable/c/d8274181b0f28d450b42489723a5ba81042158d7 · Note
• https://twitter.com/VulmonFeeds/status/2078866418104205558 · Twitter Post
• https://git.kernel.org/stable/c/7216ce8cb12fee44e309503955bb83806b106129 · Note
• https://git.kernel.org/stable/c/fd15b457a86939c38aa12116adabd8ff686c5e51 · Note
• https://git.kernel.org/stable/c/83c0a1cb296d955d5f4d1f0bd8a769ba8ed8c29f · Note
• https://git.kernel.org/stable/c/708709c65a1832a99b0eef8ae46e343ddaca3d06 · Note
• https://git.kernel.org/stable/c/4982bfabce6b33b3c9eddb4fb900fe5568b7cf91 · Note
• https://git.kernel.org/stable/c/f9b68632ac93cc742f2e411021c4dbfe452ea0c2 · Note