| Name | CVE-2026-63925 |
| Description | 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). |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| linux (PTS) | bullseye | 5.10.223-1 | vulnerable |
| bullseye (security) | 5.10.259-1 | fixed | |
| bookworm | 6.1.176-1 | fixed | |
| bookworm (security) | 6.1.177-1 | fixed | |
| trixie | 6.12.94-1 | fixed | |
| trixie (security) | 6.12.95-1 | fixed | |
| forky | 7.1.3-1 | fixed | |
| sid | 7.1.4-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| linux | source | bullseye | 5.10.259-1 | |||
| linux | source | bookworm | 6.1.176-1 | |||
| linux | source | trixie | 6.12.94-1 | |||
| linux | source | (unstable) | 7.0.12-1 |
https://git.kernel.org/linus/e68842b3356471ba56c882209f324613dac47f64 (7.1-rc6)