Client code execution via uninitialized cleanup pointer
Published Jun 28, 2026 · Updated Jun 28, 2026
Use of an uninitialized pointer in libssh2 1.11.1 and earlier allows remote attackers controlling an SSH server to execute client code. A failed response parse leaves a newly reallocated publickey-list entry uninitialized, and cleanup trusts and frees its attacker-influenceable attrs pointer. Exposure requires a client application to request the publickey subsystem from an attacker-controlled SSH server; exploitation corrupts client-process memory and can crash the process or redirect execution.
Summary
What happened
Use of an uninitialized pointer in libssh2 1.11.1 and earlier allows remote attackers controlling an SSH server to execute client code. A failed response parse leaves a newly reallocated publickey-list entry uninitialized, and cleanup trusts and frees its attacker-influenceable attrs pointer. Exposure requires a client application to request the publickey subsystem from an attacker-controlled SSH server; exploitation corrupts client-process memory and can crash the process or redirect execution.
The record
- CVE
- CVE-2026-58051
- Published
- Jun 28, 2026
- Updated
- Jun 28, 2026
- Vendor
- libssh2
- Product
- libssh2
- Classifications
- CWE-908, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 28, 2026CVE publishedPublication date reported by the CVE source.
- Jun 28, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=1.11.1
What conditions does exploitation require?
What is affected?
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
- libssh2 publickey list calc PoCsfunctional · 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