CVE-2026-25532 ESF-IDF is Vulnerable to WPS Enrollee Fragment Integer Underflow
Attackers can trigger an integer underflow in WPS packet processing, potentially causing crashes or arbitrary code execution in Espressif IoT devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-25532?
CVE-2026-25532 is a medium-severity vulnerability in espressif esp-idf, published on 4 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
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.
Weakness: CWE-191
Which versions are affected by CVE-2026-25532?
It affects 1 product.
Products include Espressif Esp-Idf.
How do I fix CVE-2026-25532?
No fix has been published for CVE-2026-25532 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-25532 being exploited?
There is no known exploitation of CVE-2026-25532 in the wild and no public exploit code.
Other vulnerabilities in espressif esp-idf
Sources
Also known as GHSA-m2h2-683f-9mw7.