CVE-2026-10680: The Classic (BR/EDR) L2CAP signaling handlers l2cap_br_conf_req() and l2cap_br_conf_rsp() in subsys/bluetooth/

Q: How do I fix CVE-2026-10680?

zephyr: upgrade to 4.3.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-10680 being exploited?

CVE-2026-10680 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-10680 affect?

CVE-2026-10680 affects zephyr. Severity is high (CVSS 7.6). The Classic (BR/EDR) L2CAP signaling handlers l2cap_br_conf_req() and l2cap_br_conf_rsp() in subsys/bluetooth/host/classic/l2cap_br.c validated the minimum command size against buf->len (the bytes remaining in the whole received PDU) instea

Routine

HIGH 7.6UPGRADE

CVE-2026-10680 is a high-severity flaw (CVSS 7.6) affecting zephyr. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Classic (BR/EDR) L2CAP signaling handlers l2cap_br_conf_req() and l2cap_br_conf_rsp() in subsys/bluetooth/host/classic/l2cap_br.c validated the minimum command size against buf->len (the bytes remaining in the whole received PDU) instead of len (the per-command data length from the L2CAP signaling header). Because multiple signaling commands can be packed into one PDU, buf->len may exceed a command's len. An attacker can send a CONF_REQ comma

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.6 (High)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 95%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-07-21
Last modified	2026-10-24

Publisher (CNA): Zephyr Project · Vendor: zephyrproject

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-21 22:17 UTCPublished CVE record published
2026-10-24 19:10 UTCUpdated Record last modified

zephyrproject zephyr UPGRADE

Affected: >= 4.2.0 and < 4.3.1 · >= 4.4.0 and <= 4.4.1

Fixed in: 4.3.1

Safe to downgrade to: a release before 4.2.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-10680?

zephyr: upgrade to 4.3.1. Exact commands for each OS are on this page.

Is CVE-2026-10680 being exploited?

CVE-2026-10680 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-10680 affect?

CVE-2026-10680 affects zephyr. Severity is high (CVSS 7.6). The Classic (BR/EDR) L2CAP signaling handlers l2cap_br_conf_req() and l2cap_br_conf_rsp() in subsys/bluetooth/host/classic/l2cap_br.c validated the minimum command size against buf->len (the bytes remaining in the whole received PDU) instea

How urgent is CVE-2026-10680?

Priority 28/100. High severity

Software pages

Bluetooth vulnerabilities

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References

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