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Fencer Vulns
medium 6.5

CVE-2025-5449 json

Libssh: integer overflow in libssh sftp server packet length validation leading to denial of service

published 2025-07-25 15 mo ago modified 2026-11-05 3 d ago also EUVD-2025-22738 , JLSEC-2025-100

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

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.

Patch / fix

  • julia libssh_jll 0.11.3+0
  • libssh Debian 14, Debian 13 0.11.2-1

debian advisories DEBIAN-CVE-2025-5449

  • libssh openSUSE Tumbleweed 0.11.2-1.1

opensuse advisories openSUSE-SU-2025:15243-1

  • libssh Alpine 3.24, Alpine 3.23, Alpine 3.22 0.11.2-r0

alpine advisories ALPINE-CVE-2025-5449

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-5449 updated cvss 6.5

libssh: Integer Overflow in libssh SFTP Server Packet Length Validation Leading to Denial of Service

  • Red Hat Enterprise Linux 6 libssh2 Red Hat Enterprise Linux 7 libssh2 Red Hat Enterprise Linux 8 libssh, libssh-config Red Hat Enterprise Linux 9 libssh, libssh-config Red Hat Enterprise Linux 10 libssh Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
15 mo ago

Exploit prediction

1.03% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia libssh_jll
>=0.11.0+0, <0.11.3+0
0.11.3+0

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.