CVE-2026-15370 Libssh: libssh: stack buffer overflow in sftp server longname construction
A stack buffer overflow in libssh's SFTP server allows attackers to cause crashes or execute code via long filenames.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-15370?
CVE-2026-15370 is a medium-severity memory corruption vulnerability in Redhat Enterprise Linux, published on 21 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
A flaw was found in libssh. During SFTP server directory listing, the longname field is constructed with unsafe concatenation into a fixed-size stack buffer. When a client causes the server to list attacker-controlled filenames, sufficiently long names can overflow that stack buffer and may lead to crashes or possible code execution on the server.
Weakness: CWE-121
Which versions are affected by CVE-2026-15370?
It affects 11 products.
Linux distribution packages (3)
libssh Red Hat:hummingbird:1 | All versions | 0:0.12.2-1.hum1 |
libssh-config Red Hat:hummingbird:1 | All versions | 0:0.12.2-1.hum1 |
libssh-devel Red Hat:hummingbird:1 | All versions | 0:0.12.2-1.hum1 |
Products include Libssh Libssh, Redhat Enterprise Linux, Redhat Enterprise Linux for Els, Redhat Enterprise Linux for Eus, Redhat Enterprise Linux for Ibm Z Systems, Redhat Enterprise Linux for Ibm Z Systems Els and 5 more.
How do I fix CVE-2026-15370?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-15370 being exploited?
There is no known exploitation of CVE-2026-15370 in the wild and no public exploit code.
Other vulnerabilities in Redhat Enterprise Linux
- 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-2026-15370, DEBIAN-CVE-2026-15370, ECHO-b5b0-c714-39f4, GHSA-6j7f-8jjp-mm8c, MINI-p4h2-gw6w-9259, RHSA-2026:47768 and 1 more.