CVE-2026-31662

HIGH EPSS 30.7%
Published Apr 24, 20262mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Apr 24, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

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.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
30.7% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-191

Affected Products 15

VendorProductVersionRange
linuxlinux_kernel*≥4.15.1  –  <5.10.253
linuxlinux_kernel*≥5.11  –  <5.15.203
linuxlinux_kernel*≥5.16  –  <6.1.169
linuxlinux_kernel*≥6.2  –  <6.6.135
linuxlinux_kernel*≥6.7  –  <6.12.82
linuxlinux_kernel*≥6.13  –  <6.18.23
linuxlinux_kernel*≥6.19  –  <6.19.13
linuxlinux_kernel4.15any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any

References 8

  • git.kernel.org https://git.kernel.org/stable/c/1b6f13f626665cac67ba5a012765427680518711
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/36ec4fdd6250dcd5e73eb09ea92ed92e9cc28412
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3bcf7aca63f0bcd679ae28e9b99823c608e59ce3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/48a5fe38772b6f039522469ee6131a67838221a8
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/575faea557f1a184a5f09661bd47ebd3ef3769f8
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a2ea1ef0167d7a84730638d05c20ccdc421b14b6
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a7db57ccca21f5801609065473c89a38229ecb92
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e0bb732eaf77f9ac2f2638bdac9e39b81e0a9682
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/1b6f13f626665cac67ba5a012765427680518711
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/36ec4fdd6250dcd5e73eb09ea92ed92e9cc28412
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3bcf7aca63f0bcd679ae28e9b99823c608e59ce3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/48a5fe38772b6f039522469ee6131a67838221a8
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/575faea557f1a184a5f09661bd47ebd3ef3769f8
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a2ea1ef0167d7a84730638d05c20ccdc421b14b6
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a7db57ccca21f5801609065473c89a38229ecb92
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e0bb732eaf77f9ac2f2638bdac9e39b81e0a9682
    Patch