CVE-2026-25508 | ESF-IDF Has Memory Safety Vulnerabilities in BLE Provisioning

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.

Published: 2026-02-04 Last update: 2026-02-20 Assigner: [email protected] Source: [email protected]

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.

Exploit prediction scoring system (EPSS) score for CVE-2026-25508

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)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-25508

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.3 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.1 4.2 [email protected]
6.3 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.1 4.2 [email protected]

Weakness enumeration for CVE-2026-25508

Affected software / configurations for CVE-2026-25508

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:*:*:*:*:*:*:*

References for CVE-2026-25508

cvelogic Threat Intelligence