PatchTheCVECVE-2026-85034: The Bluetooth host's GATT client passed the value of a received Handle Value Notification, Handle Value Indica
CVE-2026-85034 is a medium-severity flaw (CVSS 6.7) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The Bluetooth host's GATT client passed the value of a received Handle Value Notification, Handle Value Indication or Multiple Handle Value Notification to bt_gatt_subscribe_params::notify callbacks using only the length derived from the received ATT PDU. bt_att_recv() in subsys/bluetooth/host/att.c validates only a minimum PDU length and does not enforce the negotiated ATT MTU, and the fixed ATT L2CAP channel in subsys/bluetooth/host/l2cap.c app
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.7 (Medium) |
| Attack vector | Adjacent network |
| Attack complexity | High |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-787 |
| Published | 2026-11-03 |
| Last modified | 2026-11-03 |
Last updated 2026-11-03 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- Vulners Bulletins: CVE-2026-85034 2026-11-03
- Vulners Bulletins: CVE-2026-85034 Out-of-bounds write in the Bluetooth GATT client: oversized notification and indication values delivered to subscribers 2026-11-03
- Vulners Bulletins: CVE-2026-85034 Out-of-bounds write in the Bluetooth GATT client: oversized notification and indication values delivered to subscribers 2026-11-03
- VulDB Recent Entries: CVE-2026-85034 | Zephyr Project up to 4.3.1/4.4.x Bluetooth Host bap_unicast_client.c unicast_client_ep_notify out-of-bounds write 2026-11-03
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-2026-85034?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-85034 being exploited?
CVE-2026-85034 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-2026-85034 affect?
CVE-2026-85034 affects affected software. Severity is medium (CVSS 6.7). The Bluetooth host's GATT client passed the value of a received Handle Value Notification, Handle Value Indication or Multiple Handle Value Notification to bt_gatt_subscribe_params::notify callbacks using only the length derived from the re
How urgent is CVE-2026-85034?
Priority 23/100. No elevated risk signals yet.