Out-of-bounds Read in Espressif Esp-Idf
CVE-2026-81507
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.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Espressif Esp-Idf — versions < 5.2.8, >= 5.3-beta1, < 5.3.6, >= 5.4-beta1, < 5.5.5
Weakness classification (CWE)
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
- 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
Frequently asked questions
- What is CVE-2026-81507?
- CVE-2026-81507 is a medium-severity vulnerability in Espressif Esp-Idf, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-10-13.
- How severe is CVE-2026-81507?
- Medium severity. CVSS v3 base score is 6.5 out of 10.