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 the same IV.
Extend the XPN else-if to also fire when pn + 1 wraps to 0, so receipt
of pn == U32_MAX advances next_pn_halves to (upper + 1, 0).
References
Configurations
Configuration 1 (hide)
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History
27 Oct 2026, 13:00
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CPE | cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* |
|
| References | () https://git.kernel.org/stable/c/23c0e230eab397d7f68be2538790ac41d3bb91fd - Patch | |
| References | () https://git.kernel.org/stable/c/679e13a65e68a67c8b3c0467c02ee89157ec6f0f - Patch | |
| References | () https://git.kernel.org/stable/c/6d00f5c7e5ff7ec4795b7f5f8ed88bd346641652 - Patch | |
| References | () https://git.kernel.org/stable/c/79495a1b0944fe31ffd54b54b00211b493590d62 - Patch | |
| References | () https://git.kernel.org/stable/c/d15130461df388136b62a7b0ce9f66e7e2fa9ff1 - Patch | |
| References | () https://git.kernel.org/stable/c/d55acbe577db892b60547b6ef1c020b359331a6d - Patch | |
| References | () https://git.kernel.org/stable/c/dd7306779c6ce1238f4cdc34f3c1f2246b854457 - Patch | |
| References | () https://git.kernel.org/stable/c/e68842b3356471ba56c882209f324613dac47f64 - Patch |
19 Oct 2026, 21:17
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | CWE-190 |
Information
Published : 2026-07-19 16:17
Updated : 2026-10-27 13:00
NVD link : CVE-2026-63925
Mitre link : CVE-2026-63925
CVE.ORG link : CVE-2026-63925
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-190
Integer Overflow or Wraparound
