{"id":"CVE-2026-81507","aliases":["EUVD-2026-98738","GHSA-v335-fxwc-rc44"],"status":"published","title":"ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data","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.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00264,"percentile":0.18501,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-125"],"published":"2026-10-13T15:12:01Z","modified":"2026-10-28T11:18:05Z","products":[{"vendor":"espressif","product":"esp-idf"}],"references":[{"url":"https://github.com/espressif/esp-idf/security/advisories/GHSA-v335-fxwc-rc44","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/espressif/esp-idf/commit/14c99559b4337cabcf0f09c21d16b93c4cd7a6fe","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/espressif/esp-idf/commit/1e07f6d83ca892630a7210df2958455f7ca77b4a","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/espressif/esp-idf/commit/5731c63ece128f156939b9f734256e2227c1442a","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/espressif/esp-idf/commit/8de265dc44b1b22c749ea44ee7c609b3da4162f0","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/espressif/esp-idf/commit/9a6d04f65e0e341e7d72bd417c9f31b8a04ce846","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/espressif/esp-idf/commit/c2610255a5adce651ca582bb82368c3dd0ee2834","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/espressif/esp-idf/commit/c8cd8f4f3019ae2f912c8cbe9974445e8d9b8749","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/espressif/esp-idf/releases/tag/v5.2.8","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/espressif/esp-idf/releases/tag/v5.3.6","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/espressif/esp-idf/releases/tag/v5.5.5","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/espressif/esp-idf/releases/tag/v6.0.3","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/espressif/esp-idf/releases/tag/v6.1-rc1","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81507.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-81507","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-81507","title":"ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data","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.","status":"published","published":"2026-10-13T15:12:01.01Z","modified":"2026-10-14T15:00:34.785Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T13:36:18.075535Z"}],"euvd":[{"id":"EUVD-2026-98738","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.","status":"published","published":"2026-10-13T15:12:01Z","modified":"2026-10-14T15:00:34Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T17:27:15.108271Z"}],"nvd":[{"id":"CVE-2026-81507","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.","status":"published","published":"2026-10-13T16:17:23.447Z","modified":"2026-10-16T16:00:33.533Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:12:57.132005Z"}],"osv":[{"id":"CVE-2026-81507","title":"ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data","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.","status":"published","published":"2026-10-13T15:12:01.01Z","modified":"2026-10-28T11:18:05.421381019Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T15:45:18.131258Z"}]}}