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Echo: linux: security update to 6.1.176-1

medium Tenable Cloud Security Plugin ID 462380

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: Bluetooth: L2CAP: reject BR/EDR
 signaling packets over MTUsig net/bluetooth/l2cap_core.c:l2cap_sig_channel() accepts BR/EDR signaling
 packets up to the channel MTU and dispatches each command without enforcing the signaling MTU (MTUsig). A
 Bluetooth BR/EDR peer within radio range can send a fixed-channel CID 0x0001 packet that is larger than
 MTUsig and contains many L2CAP_ECHO_REQ commands before pairing. In a real-radio stock-kernel run, one
 681-byte signaling packet containing 168 zero-length ECHO_REQ commands made the target transmit 168
 ECHO_RSP frames over about 220 ms. Impact: a Bluetooth BR/EDR peer within radio range, before pairing, can
 force 168 ECHO_RSP frames from one 681-byte fixed-channel signaling packet containing packed ECHO_REQ
 commands. Define Linux's BR/EDR signaling MTU as the spec minimum of 48 bytes and reject any larger
 signaling packet with one L2CAP_COMMAND_REJECT_RSP carrying L2CAP_REJ_MTU_EXCEEDED before any command is
 dispatched. The Bluetooth Core spec wording for MTUExceeded says the reject identifier shall match the
 first request command in the packet, and that packets containing only responses shall be silently
 discarded. Linux intentionally deviates from that prescription: silently discarding desynchronizes the
 peer because the remote stack never learns its responses were dropped, and locating the first request
 command requires walking command headers past MTUsig, i.e. processing bytes from a packet we have already
 decided is too large to process. We therefore always emit one reject and use the identifier from the first
 command header, a single fixed-offset byte read. The unrestricted BR/EDR signaling parser and ECHO_REQ
 response path both trace to the initial git import; no later introducing commit is available for a Fixes
 tag. (CVE-2026-53208)

Solution

Update the linux library and its related packages to version 6.1.176-1 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-53208

Plugin Details

Severity: Medium

ID: 462380

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Medium

Score: 5.8

Percentile: 96.51

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2026-53208

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

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

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

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 6/25/2026

Vulnerability Publication Date: 6/25/2026

Reference Information

CVE: CVE-2026-53208