https://seclists.org/oss-sec/2025/q3/138: libssh2 Base64 Encoding Heap Overflow in Known Hosts SHA1 Hash Processing

Published Aug 26, 2025
·
Updated

Affected Software

1 affected component
libssh2 libssh2
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Frequently Asked Questions

1

What is the severity of CVE-2025-XXXX?

The severity of CVE-2025-XXXX is categorized as high due to the potential for a heap overflow that can lead to remote code execution.

2

How do I fix CVE-2025-XXXX?

To fix CVE-2025-XXXX, update to the latest version of libssh2 where the vulnerability has been patched.

3

What systems are affected by CVE-2025-XXXX?

CVE-2025-XXXX affects all versions of libssh2 prior to the fixed release that addresses the Base64 encoding heap overflow.

4

What is the main vulnerability of CVE-2025-XXXX?

The main vulnerability of CVE-2025-XXXX is a heap overflow during the processing of SHA1 hashes in known hosts files.

5

How can CVE-2025-XXXX be exploited?

CVE-2025-XXXX can be exploited by an attacker providing malicious SSH known_hosts files leading to potential system compromise.

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