Application crash via off-by-one bounds check
Published Mar 8, 2026 · Updated Mar 8, 2026
Out-of-bounds read in libssh 0.11.0 through 0.11.3 allows applications to crash when querying an invalid SFTP extension index. The sftp_extensions_get_name() and sftp_extensions_get_data() checks accept idx equal to the extension count, then read one element past the allocated arrays. Reachability requires application misuse of these client-side APIs; the upstream advisory states that libssh itself stays in bounds and a malicious server cannot control the condition.
Summary
What happened
Out-of-bounds read in libssh 0.11.0 through 0.11.3 allows applications to crash when querying an invalid SFTP extension index. The sftp_extensions_get_name() and sftp_extensions_get_data() checks accept idx equal to the extension count, then read one element past the allocated arrays. Reachability requires application misuse of these client-side APIs; the upstream advisory states that libssh itself stays in bounds and a malicious server cannot control the condition.
The record
- CVE
- CVE-2026-3731
- Published
- Mar 8, 2026
- Updated
- Mar 8, 2026
- Vendor
- libssh
- Product
- libssh
- Classifications
- CWE-119, CWE-125
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Mar 8, 2026CVE publishedPublication date reported by the CVE source.
- Mar 8, 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=0.11.0
- Affected versionversion=0.11.1
- Affected versionversion=0.11.2
- Affected versionversion=0.11.3
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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