Answer in brief
CVE-2026-63925 records a Unknown severity 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.
Answer in brief
CVE-2026-63925 records a Unknown severity 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.
A CVSS score is not reported in the current record. 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.
| 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
Aug 5, 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.
A CVSS score is not reported in the current record. 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.
| 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
Aug 5, 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.