Out-of-bounds Read in Espressif Esp-Idf
CVE-2026-25508
ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In versions 5.5.2, 5.4.3, 5.3.4, 5.2.6, and 5.1.6, an out-of-bounds read vulnerability was reported in the BLE ATT Prepare Write handling of the BLE provisioning transport (protocomm_ble). The issue can be triggered by a remote BLE client while the device is in provisioning mode. The transport accumulated prepared-write fragments in a fixed-size buffer but incorrectly tracked the cumulative length. By sending repeated prepare write requests with overlapping offsets, a remote client could cause the reported length to exceed the allocated buffer size. This inflated length was then passed to provisioning handlers during execute-write processing, resulting in an out-of-bounds read and potential memory corruption. This issue has been patched in versions 5.5.3, 5.4.4, 5.3.5, 5.2.7, and 5.1.7.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H.
EPSS exploit prediction
EPSS: 0.004 (29.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Espressif Esp-Idf — versions = 5.4.3, 5.4.3, 5.2.6
Weakness classification (CWE)
References
- github.com/espressif/esp-idf/security/advisories/GHSA-9j5x-rf36-54x9 (Third Party Advisory)
- github.com/espressif/esp-idf/commit/0540c85140c2c06c0cbecc8843277ea676d5c4a9 (Patch)
- github.com/espressif/esp-idf/commit/1ff264abf2504cade46f0ce3a03f821310bcf6d7 (Patch)
- github.com/espressif/esp-idf/commit/47552ff4fd824caf38215468ebd2f31fb5f36d70 (Patch)
- github.com/espressif/esp-idf/commit/4c3fdcd316f780bab4ae5aa73c9626ea9fe24ac6 (Patch)
- github.com/espressif/esp-idf/commit/894c28afe3f2f8f31ff25b64191883517dddb5cf (Patch)
- github.com/espressif/esp-idf/commit/cde7b7362adc15638c141c249681cbe5d23de663 (Patch)
- github.com/espressif/esp-idf/commit/dba9a7dc01e4dab14c77d328f6a6f46369aeee63 (Patch)
Frequently asked questions
- What is CVE-2026-25508?
- CVE-2026-25508 is a medium-severity vulnerability in Espressif Esp-Idf, classified under Out-of-bounds Read. CVSS score: 6.3/10. Published 2026-02-04.
- How severe is CVE-2026-25508?
- Medium severity. CVSS v3 base score is 6.3 out of 10.