CVE-2026-59844

Publication date 21 July 2026

Last updated 25 August 2026

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw was found in libssh. A remote authenticated client can issue SSH_FXP_READ requests with an arbitrarily large length, causing a libssh SFTP server to allocate excessive memory and potentially exhaust it through repeated requests.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libssh	26.04 LTS resolute	Vulnerable
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected

Notes

mdeslaur

introduced in 0.11.0 by: https://github.com/libssh/libssh-mirror/commit/f8bfb5a7a1e5b1a0a910c128e827a1391ddde452

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libssh	Upstream: ?id=254

Severity score breakdown

CVSS version: CVSS v3.0

Base score 6.5 · Medium

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	High

Scores

Parameter	Value
Base score	6.5 · Medium
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H