CVE Intelligence
High Memory corruption exploit reference

CVE-2026-3803 — Tenda i3 WifiMacFilterGet formWifiMacFilterGet stack-based overflow

A vulnerability was identified in Tenda i3 1.0.0.6(2204). This affects the function formWifiMacFilterGet of the file /goform/WifiMacFilterGet. The manipulation of the argument index leads to stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit is publicly available and might be used.

Published Mar 9, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulDB

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 1% (30-day exploitation probability)+10
  • 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
1.05%
ahead of 63% of scored CVEs · Oct 14, 2026
Affects
Tenda
I3 and 1 more
CVSS base
8.8
High · 2 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
No
can an attacker script the kill-chain steps
Technical impact
Total
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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Tenda I3, Tenda I3 Firmware).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Tenda I3 version 1.0.0.6(2204) Vulnerable CVE Program (cve.org) e CISA ADP
Tenda I3 Firmware version 1.0.0.6(2204) 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.

ScoreVersionSeverityExpl.ImpactScored by
8.7 CVSS 4.0 High — — VulDB via CVE Program (cve.org) e CISA ADP
7.4 CVSS 4.0 High — — cna@vuldb.com via NIST National Vulnerability Database
8.8 CVSS 3.1 High 2.8 5.9 cna@vuldb.com via NIST National Vulnerability Database
8.8 CVSS 3.1 High — — VulDB via CVE Program (cve.org) e CISA ADP
8.8 CVSS 3.0 High — — VulDB via CVE Program (cve.org) e CISA ADP
9.0 CVSS 2.0 High 8.0 10.0 cna@vuldb.com via NIST National Vulnerability Database
9.0 CVSS 2.0 High — — 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: cna@vuldb.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 1.05%

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).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · tenda/i3
    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
    Mar 9, 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

Elsewhere on this site

Tenda
every CVE for this vendor
CWE-119
other pages naming this weakness

Related CVEs (same products)

  • Critical CVE-2026-5841 Tenda i3 HTTP R7WebsSecurityHandler path traversal Apr 9, 2026
  • High CVE-2026-3970 Tenda i3 wifiSSIDget formwrlSSIDget stack-based overflow Mar 11, 2026
  • High CVE-2026-3971 Tenda i3 wifiSSIDset formwrlSSIDset stack-based overflow Mar 11, 2026
  • High CVE-2026-3804 Tenda i3 WifiMacFilterSet formWifiMacFilterSet stack-based overflow Mar 9, 2026
  • High CVE-2026-3802 Tenda i3 exeCommand formexeCommand stack-based overflow Mar 9, 2026
  • High CVE-2026-3801 Tenda i3 setAutoPing formSetAutoPing stack-based overflow Mar 9, 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-2026-3803 is "Tenda i3 WifiMacFilterGet formWifiMacFilterGet stack-based overflow", rated High. It affects I3 (Tenda); 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 1.05% 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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