Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/csql-kernel-6_6, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-kernel-6_6, sys-kernel/lakitu-nc-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_6, sys-kernel/lakitu-vgpu-kernel-6_6: security update to 19216.700.7

critical Tenable Cloud Security Plugin ID 475019

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- In the Linux kernel, the following vulnerability has been resolved: SUNRPC: xdr_buf_trim: clamp buf->len
to avoid underflow xdr_buf_trim() trims `len` bytes from the tail of an xdr_buf by walking the tail,
pages, and head iovecs. Each per-section step uses min_t() so it never removes more bytes than that
section holds, but the final accounting at the fix_len label subtracts the total bytes actually consumed
from buf->len without any clamp: fix_len: buf->len -= (len - trim); When the caller has set buf->len to a
value smaller than the sum of the iov_lens, (len - trim) can exceed buf->len and the unsigned subtraction
wraps to near UINT_MAX. gss_krb5_unwrap_v2() reaches xdr_buf_trim() in exactly that state:
buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip; buf->len = len - (GSS_KRB5_TOK_HDR_LEN +
headskip); xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip); buf->len is a small wire-derived value
while the iov_lens are at page scale, so the per-section loops legitimately consume far more bytes than
buf->len records. The wrapped buf->len then propagates as the authoritative stream bound into every
downstream XDR decoder. Fix by clamping the decrement so buf->len bottoms out at zero: buf->len -=
min_t(unsigned int, buf->len, len - trim); On the normal path where the iov_lens sum to buf->len, (len -
trim) is always <= buf->len and the result is identical to before. No callers change behavior outside the
underflow case. (CVE-2026-89551)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19216.700.7 or later.

Plugin Details

Severity: Critical

ID: 475019

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.49

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-89551

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 9/11/2026

Reference Information

CVE: CVE-2026-89551

Detections

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