Memory corruption via unchecked SMTP address concatenation
Published Aug 24, 2026 · Updated Aug 24, 2026
Buffer overflow in affected DrayTek VigorSwitch firmware allows remote authenticated users to corrupt memory through SMTP settings. The diag_logmail function appends multiple smtpReceiver addresses to a fixed-size buffer without checking the space remaining. Administrative web-interface credentials are required, and DrayTek confirms the code condition but reports no known trigger or practical attack path in deployed devices.
Summary
What happened
Buffer overflow in affected DrayTek VigorSwitch firmware allows remote authenticated users to corrupt memory through SMTP settings. The diag_logmail function appends multiple smtpReceiver addresses to a fixed-size buffer without checking the space remaining. Administrative web-interface credentials are required, and DrayTek confirms the code condition but reports no known trigger or practical attack path in deployed devices.
The record
- CVE
- CVE-2026-71941
- Published
- Aug 24, 2026
- Updated
- Aug 24, 2026
- Vendor
- DrayTek
- Product
- VigorSwitch P2100
- Classifications
- CWE-120
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Aug 24, 2026CVE publishedPublication date reported by the CVE source.
- Aug 24, 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?
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- Affected versionversion=0 <2.9.10
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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