Medium [CVE-2025-26466] Pre-authentication Denial of Service attack in OpenSSH - CVE-2025-26466
This medium-severity Fortinet advisory covers CVE-2025-26466.
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Summary
CVSSv3 Score:
5.9
CVE-2025-26466 A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages.
It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side.
Consequently, the server may become unavailable, resulting in a denial of service attack.
Revised on 2026-05-25 00:00:00
- FortiADC 7.6: 7.6.1
- FortiADCManager 7.6: 7.6.0
- FortiAIOps 2.1: 2.1 all versions
- FortiAIOps 2.0: 2.0.1 through 2.0.2
- FortiAnalyzer 7.6: 7.6.0 through 7.6.2
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
- FortiADC 7.6: 7.6.2
- FortiADCManager 7.6: 7.6.1
- FortiAIOps 2.1: migrate to a fixed release
- FortiAIOps 2.0: migrate to a fixed release
- FortiAnalyzer 7.6: 7.6.3
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Mitigation checklist
- Upgrade per the Affected/Solution table: FortiADC 7.6: 7.6.2; FortiADCManager 7.6: 7.6.1; FortiAIOps 2.1: migrate to a fixed release; FortiAIOps 2.0: migrate to a fixed release; FortiAnalyzer 7.6: 7.6.3.
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
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