Local denial of service via unchecked fork failure
Published Jul 21, 2026 · Updated Jul 21, 2026
Denial of service in libssh ProxyCommand handling allows local users to interrupt accessible processes through a failed fork operation. The ssh_socket_connect_proxycommand() function in src/socket.c stores fork()'s -1 error return as the proxy child PID, and cleanup later uses it as a signal target. Exploitation requires local low-privileged access, a ProxyCommand deployment, a fork failure, and user interaction; reported impact is limited to availability.
Summary
What happened
Denial of service in libssh ProxyCommand handling allows local users to interrupt accessible processes through a failed fork operation. The ssh_socket_connect_proxycommand() function in src/socket.c stores fork()'s -1 error return as the proxy child PID, and cleanup later uses it as a signal target. Exploitation requires local low-privileged access, a ProxyCommand deployment, a fork failure, and user interaction; reported impact is limited to availability.
The record
- CVE
- CVE-2026-59845
- Published
- Jul 21, 2026
- Updated
- Jul 21, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 10
- Classifications
- CWE-390, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 21, 2026CVE publishedPublication date reported by the CVE source.
- Jul 21, 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?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
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
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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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