CVE-2025-5449 Libssh: integer overflow in libssh sftp server packet length validation leading to denial of service
An integer overflow in libssh's SFTP server allows remote attackers to cause a denial of service via large payloads on 32-bit systems.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-5449?
CVE-2025-5449 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 25 Jul 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A flaw was found in the SFTP server message decoding logic of libssh. The issue occurs due to an incorrect packet length check that allows an integer overflow when handling large payload sizes on 32-bit systems. This issue leads to failed memory allocation and causes the server process to crash, resulting in a denial of service.
Weakness: CWE-190
Which versions are affected by CVE-2025-5449?
It affects 1 product.
Products include Libssh Libssh.
How do I fix CVE-2025-5449?
Apply the vendor's patch.
Is CVE-2025-5449 being exploited?
There is no known exploitation of CVE-2025-5449 in the wild and no public exploit code.
Other vulnerabilities in Red Hat Enterprise Linux 10
- CVE-2026-59851 Libssh: libssh: authentication bypass via missing gssapi principal check
- CVE-2025-5987 Libssh: invalid return code for chacha20 poly1305 with openssl backend
- CVE-2025-14821 Libssh: libssh: insecure default configuration leads to local man-in-the-middle attacks on windows
- CVE-2012-4560 Memory corruption in n/a
- CVE-2012-4562 Integer overflow in n/a
Sources
Also known as BELL-CVE-2025-5449, DEBIAN-CVE-2025-5449, GHSA-q9x7-4rf7-4xq2, JLSEC-2025-100, MINI-39pq-5g6j-mg8g.