CVE-2026-31513

High

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix stack-out-of-bounds read in l2cap_ecred_conn_req Syzbot reported a KASAN stack-out-of-bounds read in l2cap_build_cmd() that is triggered by a malformed Enhanced Credit Based Connection Request. The vulnerability stems from l2cap_ecred_conn_req(). The function allocates a local stack buffer (`pdu`) designed to hold a maximum of 5 Source Channel IDs (SCIDs), totaling 18 bytes. When an attacker sends a request with more than 5 SCIDs, the function calculates `rsp_len` based on this unvalidated `cmd_len` before checking if the number of SCIDs exceeds L2CAP_ECRED_MAX_CID. If the SCID count is too high, the function correctly jumps to the `response` label to reject the packet, but `rsp_len` retains the attacker's oversized value. Consequently, l2cap_send_cmd() is instructed to read past the end of the 18-byte `pdu` buffer, triggering a KASAN panic. Fix this by moving the assignment of `rsp_len` to after the `num_scid` boundary check. If the packet is rejected, `rsp_len` will safely remain 0, and the error response will only read the 8-byte base header from the stack.

Package Linux Kernel
Published 2026-04-22
Last modified 2026-04-28
CVSS version 3.1
Patch available
Not yet patched

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-2026-31513 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 6.12.75, 6.18.16, 6.19.6 and later are affected. No fixed version recorded yet.

Affected from
≥ 6.12.75 ≥ 6.18.16 ≥ 6.19.6

References

The following references provide additional information about CVE-2026-31513 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

4 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31513?

    CVE-2026-31513 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 6.12.75 onward . CVE-2026-31513 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31513?

    CVE-2026-31513 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-2026-31513?

    No patch is currently available for CVE-2026-31513. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

  • Is CVE-2026-31513 actively exploited?

    No — CVE-2026-31513 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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