CVE-2026-81507 ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data
Remote attackers can read sensitive Bluetooth stack memory via malformed L2CAP requests in ESP-IDF, requiring an upgrade to patched versions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-81507?
CVE-2026-81507 is a medium-severity vulnerability in espressif esp-idf, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. Prior to 5.2.8, 5.3.6, 5.5.5, 6.0.3, and 6.1-rc1, ESP-IDF BlueDroid L2CAP configuration-option processing in l2c_main.c and l2c_utils.c does not consistently validate option lengths against the remaining received packet bytes. A remote unauthenticated BR/EDR peer within radio range can send a malformed L2CAP configuration request that causes an out-of-bounds read, and under some runtime conditions limited adjacent Bluetooth stack memory can be included in an outbound L2CAP Configuration Response. The issue affects ESP32-class products using the BlueDroid host stack with Classic Bluetooth enabled. This issue is fixed in 5.2.8, 5.3.6, 5.5.5, 6.0.3, and 6.1-rc1.
Weakness: CWE-125
Which versions are affected by CVE-2026-81507?
How do I fix CVE-2026-81507?
No fix has been published for CVE-2026-81507 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-81507 being exploited?
There is no known exploitation of CVE-2026-81507 in the wild and no public exploit code.
Sources
Also known as GHSA-v335-fxwc-rc44.