CVE-2023-26806Public exploitNetwork attack vector

Router crash or code execution via unbounded sscanf

Published Mar 19, 2023 · Updated Feb 27, 2025

Stack buffer overflow in Tenda W20E firmware 15.11.0.6 allows remote attackers to crash the router or execute code via a crafted time value. Within formSetSysTime, sscanf parses the manualTime parameter into six eight-byte stack buffers with unbounded conversion specifiers, so an overlong field writes past a destination buffer. The published proof of concept authenticates to the web management interface before sending the request; the demonstrated outcomes are a router crash or remote code execution.

CVSS severity9.8
Critical
EPSS probability0.93%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stack buffer overflow in Tenda W20E firmware 15.11.0.6 allows remote attackers to crash the router or execute code via a crafted time value. Within formSetSysTime, sscanf parses the manualTime parameter into six eight-byte stack buffers with unbounded conversion specifiers, so an overlong field writes past a destination buffer. The published proof of concept authenticates to the web management interface before sending the request; the demonstrated outcomes are a router crash or remote code execution.

The record

CVE
CVE-2023-26806
Published
Mar 19, 2023
Updated
Feb 27, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1210, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 27, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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
9.8NIST NVDCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1210Exploitation of Remote Services
T1499Endpoint Denial of Service

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo