CVE-2026-6989 — Tenda F453 Telnet Service telnet TendaTelnet command injection
A vulnerability has been found in Tenda F453 up to 1.0.0.3. Impacted is the function TendaTelnet of the file /goform/telnet of the component Telnet Service. Such manipulation leads to command injection. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 6.3% (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.
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.
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 F453, Tenda F453 Firmware).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- EPSS ahead of 94% 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 | F453 | version 1.0.0.0version 1.0.0.1version 1.0.0.2version 1.0.0.3 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Tenda | F453 Firmware | version 1.0.0.3 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
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) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 6.33%
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.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · tenda/f453
- SSVC assessment updated
- Record published
- CVSS changed · 8.8
- Source status changed · → Analyzed
- Record created in this database
- CVE published
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
Related CVEs (same products)
- High CVE-2026-5021 Tenda F453 httpd PPTPUserSetting fromPPTPUserSetting stack-based overflow Mar 28, 2026
- High CVE-2026-4554 Tenda F453 WriteFacMac FormWriteFacMac privilege escalation Mar 22, 2026
- High CVE-2026-4553 Tenda F453 Parameters Natlimit fromNatlimit stack-based overflow Mar 22, 2026
- High CVE-2026-4552 Tenda F453 Parameters VirtualSer fromVirtualSer memory corruption Mar 22, 2026
- High CVE-2026-4551 Tenda F453 Parameters SafeClientFilter fromSafeClientFilter memory corruption Mar 22, 2026
- High CVE-2026-3768 Tenda F453 WrlExtraSet formWrlExtraSet stack-based overflow Mar 8, 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-2026-6989 is "Tenda F453 Telnet Service telnet TendaTelnet command injection", rated High. It affects F453 (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 6.33% 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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