Buffer overflow in Libssh

CVE-2026-3731

A weakness has been identified in libssh up to 0.11.3. The impacted element is the function sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected component.

Vulnerability class: Buffer Overflow

EPSS: 0.006 (46.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

  • Libssh
  • N/a Libssh — versions 0.11.0, 0.11.1, 0.11.2

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3731?
CVE-2026-3731 is a medium-severity vulnerability in Libssh, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.3/10. Published 2026-03-08.
How severe is CVE-2026-3731?
Medium severity. CVSS v3 base score is 5.3 out of 10.