Integer overflow in Linux kernel - CVE-2026-63984
Published: July 20, 2026
Vulnerability identifier: #VU138668
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-63984
CWE-ID: CWE-190
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to corrupt memory in a forwarded packet.
The vulnerability exists due to an integer overflow in ipv6_rpl_srh_decompress() and ipv6_rpl_srh_rcv() when processing a crafted IPv6 RPL source routing header. A remote attacker can send a specially crafted packet to corrupt memory in a forwarded packet.
The issue occurs because the computed hdrlen value can truncate to zero for a large segment count, causing the compressed header to overlap the decompressed routing data.
How to mitigate CVE-2026-63984
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/3618b34942b76471d044369bfd30d58c39068bf1
- https://git.kernel.org/stable/c/6fe1cb312038516cb4d9fa089d700af7059f1a64
- https://git.kernel.org/stable/c/75b3680047bf09af8e7e471a7a6ddf2ce5847f56
- https://git.kernel.org/stable/c/97e06791368c01f0ad2a4b3269c2abe19485ca32
- https://git.kernel.org/stable/c/9d5e7a46a9f6d8f503b41bfefef70659845f1679
- https://git.kernel.org/stable/c/c0487a9c1e116cf349e2d1f302d9019670460858
- https://git.kernel.org/stable/c/de02fc049352af5a9595f015511222d0a85c326b
- https://git.kernel.org/stable/c/fd238c51b0fa5390cceca9f1ac5a9ffda8063eed