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CVE-2026-25532

MEDIUM CVSS 3.1: 6.3 EPSS 0.03%
Updated Feb 05, 2026
ESF-IDF
Parameter Value
CVSS 6.3 (MEDIUM)
Type CWE-191 (Integer Underflow)
Vendor ESF-IDF
Public PoC No

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, a vulnerability exists in the WPS (Wi-Fi Protected Setup) Enrollee implementation where malformed EAP-WSC packets with truncated payloads can cause integer underflow during fragment length calculation. When processing EAP-Expanded (WSC) messages, the code computes frag_len by subtracting header sizes from the total packet length.

If an attacker sends a packet where the EAP Length field covers only the header and flags but omits the expected payload (such as the 2-byte Message Length field when WPS_MSG_FLAG_LEN is set), frag_len becomes negative. This negative value is then implicitly cast to size_t when passed to wpabuf_put_data(), resulting in a very large unsigned value. This issue has been patched in versions 5.5.3, 5.4.4, 5.3.5, 5.2.7, and 5.1.7.

Attack Parameters

Attack Vector
Adjacent
Requires local network access
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required

Impact Assessment

Confidentiality
None
No data leak
Integrity
Low
Partial data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Weakness Type (CWE)