High Injection exploit reference

CVE-2026-7609 — TRENDnet TEW-821DAP Firmware Udpate diagnostic tools_diagnostic os command injection

A flaw has been found in TRENDnet TEW-821DAP up to 1.12B01. The impacted element is the function tools_diagnostic of the file /tmp/diagnostic of the component Firmware Udpate. This manipulation causes os command injection. Remote exploitation of the attack is possible. The exploit has been published and may be used. The vendor explains: "That firmware version will only work on our hardware version v1.xR. We have already EOL that product 8 years ago and are no longer selling". This vulnerability only affects products that are no longer supported by the maintainer.

Published May 2, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulDB

Moderate

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 5.7% (30-day exploitation probability)+14
Technical severity (high)+6
CISA SSVC: exploitation "poc"+5

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

5.73%

ahead of 93% of scored CVEs · Oct 14, 2026

Affects

TRENDnet

TEW-821DAP and 1 more

CVSS base

8.8

High · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Proof of concept

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (TRENDnet TEW-821DAP, Trendnet Tew-821dap Firmware).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
EPSS ahead of 93% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
TRENDnet	TEW-821DAP	version 1.12B01	Vulnerable	CVE Program (cve.org) e CISA ADP
Trendnet	Tew-821dap Firmware	version 1.12b01	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
5.3	CVSS 4.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
2.1	CVSS 4.0	Low	—	—	cna@vuldb.com via NIST National Vulnerability Database
8.8	CVSS 3.1	High	2.8	5.9	nvd@nist.gov via NIST National Vulnerability Database
6.3	CVSS 3.1	Medium	2.8	3.4	cna@vuldb.com via NIST National Vulnerability Database
6.3	CVSS 3.1	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
6.3	CVSS 3.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
6.5	CVSS 2.0	Medium	8.0	6.4	cna@vuldb.com via NIST National Vulnerability Database
6.5	CVSS 2.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.8 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-77 · Command Injection

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 5.73%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Look for parameters with command/query metacharacters and unexpected child processes of the service.

web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · trendnet/tew-821dap
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 8.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
May 2, 2026 · VulDB

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

github.com/IOTRes/IOT_Firmware_Update/blob/main/Trendnet/TEW-821DAP_CI2.md
Exploit, Third Party Advisory, exploit, patch, NIST National Vulnerability Database
vuldb.com/vuln/360566/cti
Permissions Required, VDB Entry, signature, permissions-required, NIST National Vulnerability Database
vuldb.com/submit/806216
Third Party Advisory, VDB Entry, third-party-advisory, NIST National Vulnerability Database
vuldb.com/vuln/360566
Third Party Advisory, VDB Entry, vdb-entry, technical-description, NIST National Vulnerability Database

Elsewhere on this site

TRENDnet
every CVE for this vendor

Injection
same class

CWE-77
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-77946 TRENDnet TEW-821DAP NTP Timezone Configuration apply_time.cgi uci_safe_get stack-based overflow Aug 22, 2026
High CVE-2026-77945 TRENDnet TEW-821DAP ssi upload.cgi command injection Aug 22, 2026
High CVE-2026-7610 TRENDnet TEW-821DAP Firmware Update ssi cleartext transmission May 2, 2026
High CVE-2026-7611 TRENDnet TEW-821DAP Firmware Update cameo_dev.sh platform_do_upgrade_cameo_dev data authenticity May 2, 2026
High CVE-2026-7608 TRENDnet TEW-821DAP tools_diagnostic os command injection May 2, 2026
High CVE-2026-7607 TRENDnet TEW-821DAP Firmware Udpate auto_update_firmware buffer overflow May 2, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-7609 is "TRENDnet TEW-821DAP Firmware Udpate diagnostic tools_diagnostic os command injection", rated High. It affects TEW-821DAP (TRENDnet); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 5.73% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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