CVE-2026-31393

High

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Validate L2CAP_INFO_RSP payload length before access l2cap_information_rsp() checks that cmd_len covers the fixed l2cap_info_rsp header (type + result, 4 bytes) but then reads rsp->data without verifying that the payload is present: - L2CAP_IT_FEAT_MASK calls get_unaligned_le32(rsp->data), which reads 4 bytes past the header (needs cmd_len >= 8). - L2CAP_IT_FIXED_CHAN reads rsp->data[0], 1 byte past the header (needs cmd_len >= 5). A truncated L2CAP_INFO_RSP with result == L2CAP_IR_SUCCESS triggers an out-of-bounds read of adjacent skb data. Guard each data access with the required payload length check. If the payload is too short, skip the read and let the state machine complete with safe defaults (feat_mask and remote_fixed_chan remain zero from kzalloc), so the info timer cleanup and l2cap_conn_start() still run and the connection is not stalled.

Package Linux Kernel
Published 2026-04-03
Last modified 2026-05-26
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

8.1

out of 10
High
Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Weakness type

CWE-125

CVE-2026-31393 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.24 and later are affected. Fixed in 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10, 7.0 and their respective stable series.

Affected from
≥ 2.6.24
Fixed in
✓ 5.10.253 5.10.x ✓ 5.15.203 5.15.x ✓ 6.1.167 6.1.x ✓ 6.6.130 6.6.x ✓ 6.12.78 6.12.x ✓ 6.18.20 6.18.x ✓ 6.19.10 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-31393 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

8 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31393?

    CVE-2026-31393 is a High severity Linux kernel vulnerability with a CVSS score of 8.1 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 2.6.24 onward and has been patched in 5.10.253, 5.15.203, 6.1.167 and others. CVE-2026-31393 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31393?

    CVE-2026-31393 has a CVSS score of 8.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H .

  • Is there a patch available for CVE-2026-31393?

    Yes — CVE-2026-31393 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.167 and others. If you are running Linux kernel 2.6.24 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31393 actively exploited?

    No — CVE-2026-31393 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Out-of-bounds Read (CWE-125)?

    The product reads data past the end or before the beginning of the intended buffer. View CWE-125 on MITRE CWE →

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