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.
Conclusion & alert: CVE-2026-25508 is rated Low Risk (26.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-02-05 | — | 0.02% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.3 | 3.1 | MEDIUM |
|
2.1 | 4.2 | [email protected] |
| 6.3 | 3.1 | MEDIUM |
|
2.1 | 4.2 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| espressif | esp-idf | 5.1.6 | cpe:2.3:a:espressif:esp-idf:5.1.6:*:*:*:*:*:*:* |
| espressif | esp-idf | 5.2.6 | cpe:2.3:a:espressif:esp-idf:5.2.6:*:*:*:*:*:*:* |
| espressif | esp-idf | 5.3.4 | cpe:2.3:a:espressif:esp-idf:5.3.4:*:*:*:*:*:*:* |
| espressif | esp-idf | 5.4.3 | cpe:2.3:a:espressif:esp-idf:5.4.3:*:*:*:*:*:*:* |
| espressif | esp-idf | 5.5.2 | cpe:2.3:a:espressif:esp-idf:5.5.2:*:*:*:*:*:*:* |