Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_12: security update to 19506.120.44

high Tenable Cloud Security Plugin ID 470011

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: nfsd: fix heap overflow in NFSv4.0
LOCK replay cache The NFSv4.0 replay cache uses a fixed 112-byte inline buffer
(rp_ibuf[NFSD4_REPLAY_ISIZE]) to store encoded operation responses. This size was calculated based on OPEN
responses and does not account for LOCK denied responses, which include the conflicting lock owner as a
variable-length field up to 1024 bytes (NFS4_OPAQUE_LIMIT). When a LOCK operation is denied due to a
conflict with an existing lock that has a large owner, nfsd4_encode_operation() copies the full encoded
response into the undersized replay buffer via read_bytes_from_xdr_buf() with no bounds check. This
results in a slab-out-of-bounds write of up to 944 bytes past the end of the buffer, corrupting adjacent
heap memory. This can be triggered remotely by an unauthenticated attacker with two cooperating NFSv4.0
clients: one sets a lock with a large owner string, then the other requests a conflicting lock to provoke
the denial. We could fix this by increasing NFSD4_REPLAY_ISIZE to allow for a full opaque, but that would
increase the size of every stateowner, when most lockowners are not that large. Instead, fix this by
checking the encoded response length against NFSD4_REPLAY_ISIZE before copying into the replay buffer. If
the response is too large, set rp_buflen to 0 to skip caching the replay payload. The status is still
cached, and the client already received the correct response on the original request. (CVE-2026-31402)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19506.120.44 or later.

Plugin Details

Severity: High

ID: 470011

Version: Revision 1.3

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/3/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.25

Vendor

Vendor Severity: CRITICAL

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-2026-31402

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/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: 4/3/2026

Reference Information

CVE: CVE-2026-31402

Detections

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