Integer overflow in Linux kernel - CVE-2026-63925
Published: July 20, 2026
Vulnerability identifier: #VU138730
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-63925
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 bypass replay protection.
The vulnerability exists due to an integer overflow in macsec_post_decrypt() when processing a crafted replayed frame on an XPN association with a packet number of 0xffffffff. A remote attacker can replay a captured legitimate frame to bypass replay protection.
Exploitation requires capturing a legitimate frame carrying the maximum 32-bit packet number on an XPN association.
How to mitigate CVE-2026-63925
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/23c0e230eab397d7f68be2538790ac41d3bb91fd
- https://git.kernel.org/stable/c/679e13a65e68a67c8b3c0467c02ee89157ec6f0f
- https://git.kernel.org/stable/c/6d00f5c7e5ff7ec4795b7f5f8ed88bd346641652
- https://git.kernel.org/stable/c/79495a1b0944fe31ffd54b54b00211b493590d62
- https://git.kernel.org/stable/c/d15130461df388136b62a7b0ce9f66e7e2fa9ff1
- https://git.kernel.org/stable/c/d55acbe577db892b60547b6ef1c020b359331a6d
- https://git.kernel.org/stable/c/dd7306779c6ce1238f4cdc34f3c1f2246b854457
- https://git.kernel.org/stable/c/e68842b3356471ba56c882209f324613dac47f64