High Injection exploit reference

CVE-2026-4253 — Tenda AC8 Web UploadCfg route_set_user_policy_rule os command injection

A security flaw has been discovered in Tenda AC8 16.03.50.11. This affects the function route_set_user_policy_rule of the file /cgi-bin/UploadCfg of the component Web Interface. The manipulation of the argument wans.policy.list1 results in os command injection. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks.

Published Mar 16, 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 8.6% (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

8.56%

ahead of 95% of scored CVEs · Oct 14, 2026

Affects

Tenda

AC8 and 1 more

CVSS base

7.2

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 (Tenda AC8, Tenda Ac8 Firmware).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
EPSS ahead of 95% 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
Tenda	AC8	version 16.03.50.11	Vulnerable	CVE Program (cve.org) e CISA ADP
Tenda	Ac8 Firmware	version 16.03.50.11	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

High

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
5.1	CVSS 4.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
2.0	CVSS 4.0	Low	—	—	cna@vuldb.com via NIST National Vulnerability Database
7.2	CVSS 3.1	High	1.2	5.9	nvd@nist.gov via NIST National Vulnerability Database
4.7	CVSS 3.1	Medium	1.2	3.4	cna@vuldb.com via NIST National Vulnerability Database
4.7	CVSS 3.1	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
4.7	CVSS 3.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
5.8	CVSS 2.0	Medium	6.4	6.4	cna@vuldb.com via NIST National Vulnerability Database
5.8	CVSS 2.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:H/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 7.2 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-78 · OS Command Injection

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 8.56%

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 · tenda/ac8
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 · 7.2
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
Mar 16, 2026 · VulDB

Source activity

Repeated readings are counted rather than listed.

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

References

5 on the record

vuldb.com/
Exploit, Third Party Advisory, VDB Entry, third-party-advisory, NIST National Vulnerability Database
vuldb.com/
Permissions Required, VDB Entry, signature, permissions-required, NIST National Vulnerability Database
github.com/digitalandrew/tenda_ac8_v5/blob/main/poc_cmdi_config_upload.py
Exploit, exploit, NIST National Vulnerability Database
vuldb.com/
Third Party Advisory, VDB Entry, vdb-entry, technical-description, NIST National Vulnerability Database
www.tenda.com.cn/
Product, product, NIST National Vulnerability Database

Elsewhere on this site

Tenda
every CVE for this vendor

Injection
same class

CWE-78
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-4254 Tenda AC8 HTTP Endpoint SysToolChangePwd doSystemCmd stack-based overflow Mar 16, 2026
Critical CVE-2026-4252 Tenda AC8 IPv6 check_is_ipv6 ip address for authentication Mar 16, 2026
High CVE-2026-3044 Tenda AC8 Httpd Service UploadCfg webCgiGetUploadFile stack-based overflow Feb 23, 2026
High CVE-2026-2202 Tenda AC8 httpd WifiGuestSet fromSetWifiGusetBasic buffer overflow Feb 9, 2026
High CVE-2026-2203 Tenda AC8 Embedded Httpd Service fast_setting_wifi_set buffer overflow Feb 9, 2026
Critical CVE-2025-12618 Tenda AC8 DatabaseIniSet buffer overflow Nov 3, 2025

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-2026-4253 is "Tenda AC8 Web UploadCfg route_set_user_policy_rule os command injection", rated High. It affects AC8 (Tenda); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.2 describes technical severity. EPSS 8.56% 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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