Answer in brief
CVE-2026-63925 records a High severity (CVSS 8.1) vulnerability in macsec: fix replay protection at XPN lower-PN wrap. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=a21ecf0e033807b976967286e6c392f48ee2049f <dd7306779c6ce1238f4cdc34f3c1f2246b854457 || >=a21ecf0e033807b976967286e6c392f48ee2049f <d15130461df388136b62a7b0ce9f66e7e2fa9ff1 || >=a21ecf0e033807b976967286e6c392f48ee2049f <23c0e230eab397d7f68be2538790ac41d3bb91fd || >=a21ecf0e033807b976967286e6c392f48ee2049f <679e13a65e68a67c8b3c0467c02ee89157ec6f0f || >=a21ecf0e033807b976967286e6c392f48ee2049f <79495a1b0944fe31ffd54b54b00211b493590d62 || >=a21ecf0e033807b976967286e6c392f48ee2049f <6d00f5c7e5ff7ec4795b7f5f8ed88bd346641652 || >=a21ecf0e033807b976967286e6c392f48ee2049f <d55acbe577db892b60547b6ef1c020b359331a6d || >=a21ecf0e033807b976967286e6c392f48ee2049f <e68842b3356471ba56c882209f324613dac47f64 | dd7306779c6ce1238f4cdc34f3c1f2246b854457, d15130461df388136b62a7b0ce9f66e7e2fa9ff1, 23c0e230eab397d7f68be2538790ac41d3bb91fd, 679e13a65e68a67c8b3c0467c02ee89157ec6f0f, 79495a1b0944fe31ffd54b54b00211b493590d62, 6d00f5c7e5ff7ec4795b7f5f8ed88bd346641652, d55acbe577db892b60547b6ef1c020b359331a6d, e68842b3356471ba56c882209f324613dac47f64 |
| Linux/Linuxgeneric | 5.7 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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).
Quoted source text, attributed separately from HOL analysis.