CVE-2026-25508

CVE-2026-25508 is a medium-severity vulnerability in Espressif Esp-idf with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-25508?
CVE-2026-25508 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability high.
Is CVE-2026-25508 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-25508?
CVE-2026-25508 primarily affects Espressif Esp-idf. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-25508?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-25508 have an EU (EUVD) identifier?
Yes. CVE-2026-25508 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5378.
When was CVE-2026-25508 published?
CVE-2026-25508 was published on 2026-02-04 and last updated on 2026-06-17.

References

Affected products (5)

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