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Vulnerability · Published Feb 4, 2026 · Assigned by GitHub_M

CVE-2026-25532ESF-IDF is Vulnerable to WPS Enrollee Fragment Integer Underflow

Medium 6.3

In plain English

A medium-severity security flaw in esp-idf from espressif. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).

Severity (CVSS 3.1)6.3Medium
Exploit odds (30 days)0.2%top 83.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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, 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.

Affected products (as reported)

VendorProductVersions
espressif esp-idf = 5.5.2= 5.4.3= 5.3.4= 5.2.6= 5.1.6

Weakness: CWE-191 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H

References