A flaw was found in libssh. A malicious SFTP server can send responses for unknown request IDs that libssh clients keep queued indefinitely, causing… (CVE-2026-59848)
A vulnerability in libssh allows a malicious SFTP server to send responses for unknown request IDs, which libssh clients keep queued indefinitely. This behavior causes unbounded memory growth on the client side, leading to a denial of service condition. The issue affects libssh clients and can be triggered remotely without authentication. Red Hat has released an update for Red Hat Hardened Images RPMs including libssh-0.12.1-4.hum1 to address this flaw.
AI Analysis
Technical Summary
CVE-2026-59848 is a vulnerability in libssh where a malicious SFTP server can send responses with unknown request IDs. The libssh client queues these responses indefinitely, causing unbounded memory consumption and resulting in client-side denial of service. The vulnerability does not impact confidentiality or integrity but affects availability. Red Hat has issued a security advisory with updated libssh packages to fix this issue in their Hardened Images RPMs.
Potential Impact
The vulnerability allows a remote attacker controlling an SFTP server to cause unbounded memory growth on libssh clients by sending responses for unknown request IDs. This leads to denial of service on the client side due to resource exhaustion. There is no impact on confidentiality or integrity according to the CVSS vector.
Mitigation Recommendations
Red Hat has released an official security update for libssh in their Hardened Images RPMs (libssh-0.12.1-4.hum1) that addresses this vulnerability. Users of affected Red Hat Hardened Images should apply this update promptly. Patch status is confirmed by the vendor advisory. No additional mitigations are specified.
A flaw was found in libssh. A malicious SFTP server can send responses for unknown request IDs that libssh clients keep queued indefinitely, causing… (CVE-2026-59848)
Description
A vulnerability in libssh allows a malicious SFTP server to send responses for unknown request IDs, which libssh clients keep queued indefinitely. This behavior causes unbounded memory growth on the client side, leading to a denial of service condition. The issue affects libssh clients and can be triggered remotely without authentication. Red Hat has released an update for Red Hat Hardened Images RPMs including libssh-0.12.1-4.hum1 to address this flaw.
CVSS v3.1
Score 5.3medium
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-59848 is a vulnerability in libssh where a malicious SFTP server can send responses with unknown request IDs. The libssh client queues these responses indefinitely, causing unbounded memory consumption and resulting in client-side denial of service. The vulnerability does not impact confidentiality or integrity but affects availability. Red Hat has issued a security advisory with updated libssh packages to fix this issue in their Hardened Images RPMs.
Potential Impact
The vulnerability allows a remote attacker controlling an SFTP server to cause unbounded memory growth on libssh clients by sending responses for unknown request IDs. This leads to denial of service on the client side due to resource exhaustion. There is no impact on confidentiality or integrity according to the CVSS vector.
Mitigation Recommendations
Red Hat has released an official security update for libssh in their Hardened Images RPMs (libssh-0.12.1-4.hum1) that addresses this vulnerability. Users of affected Red Hat Hardened Images should apply this update promptly. Patch status is confirmed by the vendor advisory. No additional mitigations are specified.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-4h4r-q9xg-gfmm
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-59848"]
- Ecosystems
- []
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a6150e19c2644c7f8da17db
Added to database: 07/22/2026, 23:23:13 UTC
Last enriched: 07/22/2026, 23:35:52 UTC
Last updated: 07/31/2026, 19:24:49 UTC
Views: 32
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