Memory corruption via wrapped authentication packet length
Published May 1, 2026 · Updated May 1, 2026
Integer overflow in libssh2 1.11.0 through 1.11.1 allows remote attackers to corrupt SSH authentication-packet length calculations. The userauth_password function in src/userauth.c adds username_len and password_len to fixed packet overhead without overflow-safe bounds checks, allowing the computed allocation length to wrap before packet data is prepared. Remote reachability depends on a consuming application passing attacker-controlled, extremely large credential lengths into the client library; the published record does not establish code execution or a specific service failure.
Summary
What happened
Integer overflow in libssh2 1.11.0 through 1.11.1 allows remote attackers to corrupt SSH authentication-packet length calculations. The userauth_password function in src/userauth.c adds username_len and password_len to fixed packet overhead without overflow-safe bounds checks, allowing the computed allocation length to wrap before packet data is prepared. Remote reachability depends on a consuming application passing attacker-controlled, extremely large credential lengths into the client library; the published record does not establish code execution or a specific service failure.
The record
- CVE
- CVE-2026-7598
- Published
- May 1, 2026
- Updated
- May 1, 2026
- Vendor
- libssh2
- Product
- libssh2
- Classifications
- CWE-190, CWE-189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 1, 2026CVE publishedPublication date reported by the CVE source.
- May 1, 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=1.11.0
- Affected versionversion=1.11.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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