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

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.

Published: 2026-03-26 Last update: 2026-05-19 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-0967 is rated Low Risk (24.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-0967

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-21 0.07% 0.03% -0.04%
2 2026-03-27 — 0.07% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-0967

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
2.2 3.0 LOW
CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 0.8 1.4 [email protected]

Weakness enumeration for CVE-2026-0967

GitHub Security Advisory for CVE-2026-0967

GHSA-6jpg-fr24-wpvf · Severity: low — A flaw was found in libssh. A remote attacker, by controlling client configuration files or...

OS Trackers for CVE-2026-0967

vendor priority summary link
alpine — CVE-2026-0967: 1 source package rows (libssh); 12 state rows across 2 repos (3.23-community, edge-community); fixed 2, open 10. https://security.alpinelinux.org/vuln/CVE-2026-0967
debian not yet assigned CVE-2026-0967 not yet assigned priority: Debian including 1 source packages (libssh), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-0967
redhat low — https://access.redhat.com/security/cve/CVE-2026-0967
suse low CVE-2026-0967 severity low: SUSE including 276 source package names (1.1.1-1.40:libssh-config-0.9.8-150600.11.9.1, 1.1.1-1.40:libssh4-0.9.8-150600.11.9.1, …), 428 product×package rows across 85 product lines (Container private-registry/harbor-trivy-adapter, Container suse/ltss/sle12.5/sles12sp5, … (85 product lines)): Known Affected 231, Fixed 187, First Fixed 10. https://www.suse.com/security/cve/CVE-2026-0967/
ubuntu medium CVE-2026-0967 medium priority: Ubuntu including 1 source packages (libssh), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): released 7. https://ubuntu.com/security/CVE-2026-0967

Affected software / configurations for CVE-2026-0967

Vendor Product Version Raw CPE
libssh libssh <= 0.11.3 cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux 10.0 cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*

References for CVE-2026-0967

cvelogic Threat Intelligence