CVE-2026-11405 (GCVE-0-2026-11405)
Vulnerability from cvelistv5 – Published: 2026-07-06 19:17 – Updated: 2026-07-08 13:40
VLAI
EPSS
VEX
Title
Hidden backdoor authentication mechanism in multiple versions of Tenda firmware allows admin access to web management interface
Summary
The web server binary /bin/httpd contains a hidden backdoor authentication mechanism in the login() function at 004c88b8.
- The function contains a normal authentication path using MD5/hash-based password verification (prod_encode64/PasswordToMd5/check_rand_key).
- After normal authentication fails, it calls GetValue("sys.rzadmin.password") to read a backdoor password from the device configuration.
- It performs a direct strcmp() comparison (plaintext, not hashed) between the config value and the user-supplied password.
A successful match grants role=2 (admin-level access) and creates a valid session. The rzadmin username is never checked — any username works with the backdoor
Severity
9.8 (Critical)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-08 03:56 UTC
CWE
- CWE-912 - Hidden Functionality
Assigner
References
Impacted products
5 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Tenda | firmware |
Affected:
US_AC6V2.0RTL_V15.03.06.51_multi_T
|
guessed | |
| Tenda | firmware |
Affected:
US_AC5V1.0RTL_V15.03.06.48_multi_TDE01
|
guessed | |
| Tenda | firmware |
Affected:
US_AC10V1.0re_V15.03.06.46_multi_TDE01
|
guessed | |
| Tenda | firmware |
Affected:
US_W15EV1.0br_V15.11.0.5(1068_1567_841)_EN_TDE
|
guessed | |
| Tenda | firmware |
Affected:
US_FH1201V1.0BR_V1.2.0.14(408)_EN_TD
|
guessed |
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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