Vulnerability · Published Oct 13, 2026 · Assigned by GitHub_M

CVE-2026-81507ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data

Medium 6.5

In plain English

A medium-severity out-of-bounds read in esp-idf from espressif. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 81.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
espressif	esp-idf	< 5.2.8>= 5.3-beta1, < 5.3.6>= 5.4-beta1, < 5.5.5>= 6.0-beta1, < 6.0.3>= 6.1-beta1, < 6.1-rc1

Weakness: CWE-125 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

https://github.com/espressif/esp-idf/security/advisories/GHSA-v335-fxwc-rc44 x_refsource_CONFIRM
https://github.com/espressif/esp-idf/commit/14c99559b4337cabcf0f09c21d16b93c4cd7a6fe x_refsource_MISC
https://github.com/espressif/esp-idf/commit/1e07f6d83ca892630a7210df2958455f7ca77b4a x_refsource_MISC
https://github.com/espressif/esp-idf/commit/5731c63ece128f156939b9f734256e2227c1442a x_refsource_MISC
https://github.com/espressif/esp-idf/commit/8de265dc44b1b22c749ea44ee7c609b3da4162f0 x_refsource_MISC
https://github.com/espressif/esp-idf/commit/9a6d04f65e0e341e7d72bd417c9f31b8a04ce846 x_refsource_MISC
https://github.com/espressif/esp-idf/commit/c2610255a5adce651ca582bb82368c3dd0ee2834 x_refsource_MISC
https://github.com/espressif/esp-idf/commit/c8cd8f4f3019ae2f912c8cbe9974445e8d9b8749 x_refsource_MISC
https://github.com/espressif/esp-idf/releases/tag/v5.2.8 x_refsource_MISC
https://github.com/espressif/esp-idf/releases/tag/v5.3.6 x_refsource_MISC
https://github.com/espressif/esp-idf/releases/tag/v5.5.5 x_refsource_MISC
https://github.com/espressif/esp-idf/releases/tag/v6.0.3 x_refsource_MISC
https://github.com/espressif/esp-idf/releases/tag/v6.1-rc1 x_refsource_MISC