CVE-2026-81507
ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data
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.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.5
ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data
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.
- Record
CVE-2026-81507- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-02
EUVDEUVD-2026-98738
6.5
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.
- Record
EUVD-2026-98738- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
NVD
6.5
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.
- Record
CVE-2026-81507- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-02
OSV
6.5
ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data
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.
- Record
CVE-2026-81507- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-81507 is a medium vulnerability (CVSS 6.5) in Espressif Esp-idf, published October 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 18th percentile. No source names a fixed version.
References
github.com/espressif/esp-idf/security/advisories/GHSA-v335-fxwc-rc44
github.com/espressif/esp-idf/commit/14c99559b4337cabcf0f09c21d16b93c4cd7a6fe
github.com/espressif/esp-idf/commit/1e07f6d83ca892630a7210df2958455f7ca77b4a
github.com/espressif/esp-idf/commit/5731c63ece128f156939b9f734256e2227c1442a
github.com/espressif/esp-idf/commit/8de265dc44b1b22c749ea44ee7c609b3da4162f0
github.com/espressif/esp-idf/commit/9a6d04f65e0e341e7d72bd417c9f31b8a04ce846
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github.com/espressif/esp-idf/commit/c2610255a5adce651ca582bb82368c3dd0ee2834
github.com/espressif/esp-idf/commit/c8cd8f4f3019ae2f912c8cbe9974445e8d9b8749
github.com/espressif/esp-idf/releases/tag/v5.2.8
github.com/espressif/esp-idf/releases/tag/v5.3.6
github.com/espressif/esp-idf/releases/tag/v5.5.5
github.com/espressif/esp-idf/releases/tag/v6.0.3
github.com/espressif/esp-idf/releases/tag/v6.1-rc1
github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81507.json
nvd.nist.gov/vuln/detail/CVE-2026-81507