CVE-2026-31662

Last refreshed2026-10-17

Status: UPDATED | Advisory ID: CVE-2026-31662

Key Details

CVE	CVE-2026-31662
CVSS Score / Version	7.5 (High) / CVSS v3.1
Updated	2026-10-16
CVSS Vector	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`
CVSS Prose	attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is none; integrity impact is none; availability impact is high.
Affected products	Linux Kernel
Classified as	CWE-191 (Integer Underflow (Wrap or Wraparound))

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Subsystems	OT Supporting Infrastructure
Sectors	All Sectors

In the Linux kernel, the following vulnerability has been resolved:

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG

The GRP_ACK_MSG handler in tipc_group_proto_rcv() currently decrements

bc_ackers on every inbound group ACK, even when the same member has

already acknowledged the current broadcast round.

Because bc_ackers is a u16, a duplicate ACK received after the last

legitimate ACK wraps the counter to 65535. Once wrapped,

tipc_group_bc_cong() keeps reporting congestion and later group

broadcasts on the affected socket stay blocked until the group is

recreated.

Fix this by ignoring duplicate or stale ACKs before touching bc_acked or

bc_ackers. This makes repeated GRP_ACK_MSG handling idempotent and

prevents the underflow path. (NVD)

Monitor Linux's web page for any future patch releases.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-31662
CVE	https://www.cve.org/CVERecord?id=CVE-2026-31662

Source

Reference

NVD

CVE