Unauthenticated memory corruption via oversized Host header
Published Jul 14, 2026 · Updated Jul 14, 2026
Stack-based buffer overflow in TOTOLINK NR1800X Firmware 9.1.0u.6279_B20210910 allows remote attackers to corrupt memory via HTTP. Form_Logout uses strcpy to copy the attacker-controlled Host header into a fixed-size stack buffer after a substring URI check routes the request to the handler. No authentication or session is required; the published artifact sends a Host header longer than 245 bytes and demonstrates the overwrite trigger, not code execution.
Summary
What happened
Stack-based buffer overflow in TOTOLINK NR1800X Firmware 9.1.0u.6279_B20210910 allows remote attackers to corrupt memory via HTTP. Form_Logout uses strcpy to copy the attacker-controlled Host header into a fixed-size stack buffer after a substring URI check routes the request to the handler. No authentication or session is required; the published artifact sends a Host header longer than 245 bytes and demonstrates the overwrite trigger, not code execution.
The record
- CVE
- CVE-2026-15701
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- TOTOLINK
- Product
- NR1800X Firmware
- Classifications
- CWE-119, CWE-121, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=9.1.0u.6279_B20210910
What conditions does exploitation require?
What is affected?
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
- NR1800X Form_Logout oversized Host proof of conceptproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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