Remote service crash via unchecked strncpy length
Published Jun 9, 2026 · Updated Jun 9, 2026
Stack-based buffer overflow in Tenda W20E 15.11.0.6 allows remote attackers to crash the device via a crafted HTTP request. The formAddWebAuthUser handler reads webAuthUserInfo with websGetVar, finds a newline, and passes the unchecked pointer difference as the strncpy length into a fixed buffer. No authentication or user interaction is required; an oversized parameter can crash the web process or destabilize the router, with no documented confidentiality or integrity impact.
Summary
What happened
Stack-based buffer overflow in Tenda W20E 15.11.0.6 allows remote attackers to crash the device via a crafted HTTP request. The formAddWebAuthUser handler reads webAuthUserInfo with websGetVar, finds a newline, and passes the unchecked pointer difference as the strncpy length into a fixed buffer. No authentication or user interaction is required; an oversized parameter can crash the web process or destabilize the router, with no documented confidentiality or integrity impact.
The record
- CVE
- CVE-2026-36823
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-121, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- formAddWebAuthUser crafted-request proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo