CVE-2026-31498

MEDIUM EPSS 2.4%
Published Apr 22, 20262mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Apr 22, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop l2cap_config_req() processes CONFIG_REQ for channels in BT_CONNECTED state to support L2CAP reconfiguration (e.g. MTU changes). However, since both CONF_INPUT_DONE and CONF_OUTPUT_DONE are already set from the initial configuration, the reconfiguration path falls through to l2cap_ertm_init(), which re-initializes tx_q, srej_q, srej_list, and retrans_list without freeing the previous allocations and sets chan->sdu to NULL without freeing the existing skb. This leaks all previously allocated ERTM resources. Additionally, l2cap_parse_conf_req() does not validate the minimum value of remote_mps derived from the RFC max_pdu_size option. A zero value propagates to l2cap_segment_sdu() where pdu_len becomes zero, causing the while loop to never terminate since len is never decremented, exhausting all available memory. Fix the double-init by skipping l2cap_ertm_init() and l2cap_chan_ready() when the channel is already in BT_CONNECTED state, while still allowing the reconfiguration parameters to be updated through l2cap_parse_conf_req(). Also add a pdu_len zero check in l2cap_segment_sdu() as a safeguard.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
2.4% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-835

Affected Products 20

VendorProductVersionRange
linuxlinux_kernel*≥4.4.238  –  <4.5
linuxlinux_kernel*≥4.9.238  –  <4.10
linuxlinux_kernel*≥4.14.200  –  <4.15
linuxlinux_kernel*≥4.19.149  –  <4.20
linuxlinux_kernel*≥5.4.69  –  <5.5
linuxlinux_kernel*≥5.7.1  –  <5.10.253
linuxlinux_kernel*≥5.11  –  <5.15.203
linuxlinux_kernel*≥5.16  –  <6.1.168
linuxlinux_kernel*≥6.2  –  <6.6.131
linuxlinux_kernel*≥6.7  –  <6.12.80
linuxlinux_kernel*≥6.13  –  <6.18.21
linuxlinux_kernel*≥6.19  –  <6.19.11
linuxlinux_kernel5.7any
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/042e2cd4bb11e5313b19b87593616524949e4c52
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/25f420a0d4cfd61d3d23ec4b9c56d9f443d91377
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/52667c859fe33f70c2e711cb81bbd505d5eb8e75
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/900e4db5385ec2cacd372345a80ab9c8e105b3a3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9760b83cfd24b38caee663f429011a0dd6064fa9
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9a21a631ee034b1573dce14b572a24943dbfd7ae
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/de37e2655b7abc3f59254c6b72256840f39fc6d5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e7aab23b7df89a3d754a5f0a7d2237548b328bd0
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/042e2cd4bb11e5313b19b87593616524949e4c52
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/25f420a0d4cfd61d3d23ec4b9c56d9f443d91377
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/52667c859fe33f70c2e711cb81bbd505d5eb8e75
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/900e4db5385ec2cacd372345a80ab9c8e105b3a3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9760b83cfd24b38caee663f429011a0dd6064fa9
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9a21a631ee034b1573dce14b572a24943dbfd7ae
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/de37e2655b7abc3f59254c6b72256840f39fc6d5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e7aab23b7df89a3d754a5f0a7d2237548b328bd0
    Patch