CVE-2026-67822Public exploitNetwork attack vector

Authenticated service crash via unbounded sprintf

Published Jul 31, 2026 · Updated Jul 31, 2026

Stack-based buffer overflow in Tenda W6-S 1.0.0.4(510) allows remote authenticated users to crash the HTTP management service. The formwrlSSIDset function passes user-controlled GO and index values to sprintf, which writes the formatted path into a 64-byte stack buffer without a length bound. A valid management session is required, and the demonstrated consequence is an httpd crash that leaves the web interface unavailable until device reboot.

CVSS severity9.8
Critical
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Tenda W6-S 1.0.0.4(510) allows remote authenticated users to crash the HTTP management service. The formwrlSSIDset function passes user-controlled GO and index values to sprintf, which writes the formatted path into a 64-byte stack buffer without a length bound. A valid management session is required, and the demonstrated consequence is an httpd crash that leaves the web interface unavailable until device reboot.

The record

CVE
CVE-2026-67822
Published
Jul 31, 2026
Updated
Jul 31, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-121, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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