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Vulnerability · Published Mar 26, 2026 · Assigned by redhat

CVE-2026-0967Libssh: libssh: denial of service via inefficient regular expression processing

Low 2.2

In plain English

A low-severity regular-expression denial of service in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.0)2.2Low
Exploit odds (30 days)0.2%top 85.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10libssh0.12.0-2.el10ALSA-2026:18160
AlmaLinux:9libssh0.10.4-18.el9ALSA-2026:18683
AlmaLinux:10libssh-config0.12.0-2.el10ALSA-2026:18160
AlmaLinux:9libssh-config0.10.4-18.el9ALSA-2026:18683
AlmaLinux:10libssh-devel0.12.0-2.el10ALSA-2026:18160
AlmaLinux:9libssh-devel0.10.4-18.el9ALSA-2026:18683
Alpine:v3.23libssh0.11.4-r0ALPINE-CVE-2026-0967
Alpine:v3.24libssh0.12.0-r0ALPINE-CVE-2026-0967
Debian:12libssh0.10.6-0+deb12u3DEBIAN-CVE-2026-0967
Debian:13libssh0.11.5-0+deb13u1DEBIAN-CVE-2026-0967
Debian:14libssh0.12.0-1DEBIAN-CVE-2026-0967
Rocky Linux:10libssh0:0.12.0-2.el10RLSA-2026:18160
Rocky Linux:9libssh0:0.10.4-18.el9RLSA-2026:18683
Ubuntu:22.04:LTSlibssh0.9.6-2ubuntu0.22.04.6UBUNTU-CVE-2026-0967
Ubuntu:22.04:LTSlibssh0.9.6-2ubuntu0.22.04.6USN-8051-1
Ubuntu:24.04:LTSlibssh0.10.6-2ubuntu0.3USN-8051-1
Ubuntu:24.04:LTSlibssh0.10.6-2ubuntu0.3UBUNTU-CVE-2026-0967
Ubuntu:25.10libssh0.11.2-1ubuntu0.2UBUNTU-CVE-2026-0967
Ubuntu:25.10libssh0.11.2-1ubuntu0.2USN-8051-1

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Enterprise Linux 6 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat OpenShift Container Platform 4 see references
Red Hat Red Hat OpenShift Container Platform 4 see references

Weakness: CWE-1333 · Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L

References