CVE-2026-63925

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: macsec: fix replay protection at XPN lower-PN wrap In macsec_post_decrypt(), when pn is U32_MAX, pn + 1 overflows u32 to 0 and the first branch never fires. If next_pn_halves.lower is also in the upper half, pn_same_half(pn, lower) is true and the XPN else-if does not fire either, leaving next_pn_halves unchanged. An attacker that captures the legitimate frame carrying pn == 0xFFFFFFFF on an XPN association can then replay it indefinitely, since lowest_pn never rises above the captured pn and macsec_decrypt() reconstructs t...

Affected product and versions

Product

Linux

Affected versions

>= a21ecf0e033807b976967286e6c392f48ee2049f < dd7306779c6ce1238f4cdc34f3c1f2246b854457, >= a21ecf0e033807b976967286e6c392f48ee2049f < d15130461df388136b62a7b0ce9f66e7e2fa9ff1, >= a21ecf0e033807b976967286e6c392f48ee2049f < 23c0e230eab397d7f68be2538790ac41d3bb91fd, >= a21ecf0e033807b976967286e6c392f48ee2049f < 679e13a65e68a67c8b3c0467c02ee89157ec6f0f, >= a21ecf0e033807b976967286e6c392f48ee2049f < 79495a1b0944fe31ffd54b54b00211b493590d62, >= a21ecf0e033807b976967286e6c392f48ee2049f < 6d00f5c7e5ff7ec4795b7f5f8ed88bd346641652, >= a21ecf0e033807b976967286e6c392f48ee2049f < d55acbe577db892b60547b6ef1c020b359331a6d, >= a21ecf0e033807b976967286e6c392f48ee2049f < e68842b3356471ba56c882209f324613dac47f64, >= 5.7

Fixed versions

No verified fixed-version field is available yet

Technical data

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

CWE

Not available