CVE-2026-77946Public exploitNetwork attack vector

Unauthenticated code execution via unchecked stack copy

Published Aug 22, 2026 · Updated Aug 22, 2026

Stack-based buffer overflow in TRENDnet TEW-821DAP 2.2.01b05 allows remote attackers to execute code through crafted NTP settings. The apply_time.cgi path passes user-controlled UCI values to uci_safe_get, which copies them with strcpy into fixed-size stack buffers without length checks. Unauthenticated HTTP access to the management CGI is sufficient to overwrite the saved return address, causing a crash or enabling root-level code execution.

CVSS severity10.0
Critical
EPSS probability0.62%
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 TRENDnet TEW-821DAP 2.2.01b05 allows remote attackers to execute code through crafted NTP settings. The apply_time.cgi path passes user-controlled UCI values to uci_safe_get, which copies them with strcpy into fixed-size stack buffers without length checks. Unauthenticated HTTP access to the management CGI is sufficient to overwrite the saved return address, causing a crash or enabling root-level code execution.

The record

CVE
CVE-2026-77946
Published
Aug 22, 2026
Updated
Aug 22, 2026
Vendor
TRENDnet
Product
TEW-821DAP
Classifications
CWE-121, CWE-119, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 22, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.2.01b05

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

TRENDnet · TEW-821DAPversion=2.2.01b05

Published CVSS scores

10.0VulDB CNAAV:N/AC:L/Au:N/C:C/I:C/A:C
10.0VulDB CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
9.3VulDB CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-119Memory Corruption
T1190Exploit Public-Facing Application

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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