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TI-2026-20641 Aliases CVE-2026-25532

ESF-IDF is Vulnerable to WPS Enrollee Fragment Integer Underflow

Priority LOW 34CWE-191Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-191 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00248 16th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
espressifesp-idf= 5.5.2; = 5.4.3; = 5.3.4; = 5.2.6; = 5.1.6—No fix listedCNA
  • esp-idf Vendorespressif Affected = 5.5.2; = 5.4.3; = 5.3.4; = 5.2.6; = 5.1.6 Fixed in — No fix listed CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:a:espressif:esp-idf:5.1.6:*:*:*:*:*:*:*5.1.6Vulnerableespressif
cpe:2.3:a:espressif:esp-idf:5.2.6:*:*:*:*:*:*:*5.2.6Vulnerableespressif
cpe:2.3:a:espressif:esp-idf:5.3.4:*:*:*:*:*:*:*5.3.4Vulnerableespressif
cpe:2.3:a:espressif:esp-idf:5.4.3:*:*:*:*:*:*:*5.4.3Vulnerableespressif
cpe:2.3:a:espressif:esp-idf:5.5.2:*:*:*:*:*:*:*5.5.2Vulnerableespressif
  • cpe:2.3:a:espressif:esp-idf:5.1.6:*:*:*:*:*:*:* Versions 5.1.6 Vulnerable ·espressif
  • cpe:2.3:a:espressif:esp-idf:5.2.6:*:*:*:*:*:*:* Versions 5.2.6 Vulnerable ·espressif
  • cpe:2.3:a:espressif:esp-idf:5.3.4:*:*:*:*:*:*:* Versions 5.3.4 Vulnerable ·espressif
  • cpe:2.3:a:espressif:esp-idf:5.4.3:*:*:*:*:*:*:* Versions 5.4.3 Vulnerable ·espressif
  • cpe:2.3:a:espressif:esp-idf:5.5.2:*:*:*:*:*:*:* Versions 5.5.2 Vulnerable ·espressif

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-25532

References

Patch 8

  • TI-2024-22076 Buffer Overflow vulnerability in esp-idf v.5.1 allows a remote attacker to execute… CVSS 3.1MEDIUM 6.5
  • TI-2026-33125 ESF-IDF: Out-of-Bounds Write in ESP-TEE Secure Service Wrappers CVSS 3.1CRITICAL 9.3
  • TI-2025-32598 ESP-NOW Integer Underflow Vulnerability Advisory CVSS 4.0HIGH 7.2
  • TI-2022-08703 Espressif Bluetooth Mesh Stack Vulnerable to Out-of-bounds Write leading to memory buffer corruption CVSS 3.1HIGH 8.8
  • TI-2021-09371 The Bluetooth Classic implementation in Espressif ESP-IDF 4.4 and earlier does not… CVSS 3.1HIGH 8.8
  • TI-2026-33292 ESF-IDF: Remote Null Pointer Dereference in WebSocket Server CVSS 3.1HIGH 7.5
See all 30 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences