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CVE-2026-9426 Edimax CVE debrief

A stack-based buffer overflow vulnerability exists in the Edimax EW-7438RPn wireless range extender, firmware version 1.31. The vulnerability resides in the `formHwSet` function within the `/goform/formHwSet` endpoint. Multiple parameters—including `Anntena`, `Mcs`, `regDomain`, `nic0Addr`, `nic1Addr`, `wlanAddr`, `wanAddr`, `wlanSSID`, `wlanChan`, `initgain`, `txcck`, `txofdm`, and `submit-url`—are susceptible to manipulation that triggers the overflow condition. The attack vector is network-based, requires low attack complexity, and can be executed remotely by an attacker with low privileges. The CVSS 4.0 vector indicates high impacts to confidentiality, integrity, and availability. The vulnerability has been publicly disclosed with exploit availability noted, and the vendor was reportedly contacted prior to disclosure without response. The NVD entry status is currently 'Deferred'.

Vendor
Edimax
Product
EW-7438RPn
CVSS
HIGH 7.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-25
Original CVE updated
2026-07-23
Advisory published
2026-05-25
Advisory updated
2026-07-23

Who should care

Organizations deploying Edimax EW-7438RPn range extenders in production environments; network administrators managing IoT device fleets; security teams monitoring for embedded device exploitation; incident responders tracking consumer-grade wireless infrastructure attacks

Technical summary

The `formHwSet` function in `/goform/formHwSet` fails to properly validate input length for multiple hardware configuration parameters. Insufficient bounds checking allows attacker-controlled data to overflow stack-allocated buffers, potentially enabling arbitrary code execution with the privileges of the web server process. The vulnerability is reachable without authentication requirements beyond low-privilege network access.

Defensive priority

HIGH

Recommended defensive actions

  • Block or restrict access to the `/goform/formHwSet` endpoint on affected Edimax EW-7438RPn devices at network boundaries
  • Segment IoT devices including Edimax range extenders from critical network infrastructure
  • Monitor for anomalous requests to `/goform/formHwSet` containing oversized parameter values
  • Apply firmware updates from Edimax if and when released; verify vendor security advisory status
  • Consider replacing affected devices if vendor patch availability cannot be confirmed
  • Review network logs for indicators of compromise targeting Edimax device management interfaces

Evidence notes

Vulnerability identified through Vuldb submission (ID 813894) and assigned Vuldb entry 365407. Technical details published via GitHub repository. NVD status marked as 'Deferred' as of 2026-05-26. CVSS 4.0 vector confirms network attack vector with low complexity and high impact across CIA triad. CWE-119 and CWE-121 (stack-based buffer overflow) classifications applied.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-9426 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-9426

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-9426 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-9426

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.