CVE-2026-63912

Public on 2026-07-19
Modified on 2026-07-27
Description
In the Linux kernel, the following vulnerability has been resolved:

xfrm: esp: restore combined single-frag length gate

The ESP out-of-place fast path appends the trailer in esp_output_head()
before esp_output_tail() allocates the destination page frag. The
head-side gate currently checks skb->data_len and tailen separately, but
the tail code allocates a single destination frag from the combined
post-trailer skb->data_len.

Reject the page-frag fast path when the combined aligned length exceeds a
page. Otherwise skb_page_frag_refill() may fall back to a single page while
the destination sg still spans the combined skb->data_len.

Restore this combined-length page gate for both IPv4 and IPv6.
Severity
Important severity
Important
See what this means
CVSS v3 Base Score
7.0
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core kernel Pending Fix
Amazon Linux 2 - Kernel-5.10 Extra kernel Pending Fix
Amazon Linux 2 - Kernel-5.15 Extra kernel Pending Fix
Amazon Linux 2 - Kernel-5.4 Extra kernel Pending Fix
Amazon Linux 2023 kernel Pending Fix
Amazon Linux 2023 kernel6.12 Pending Fix
Amazon Linux 2023 kernel6.18 Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H