Cyber Resilience

CVE-2026-0967

Redhat Enterprise Linux 10.0 … 9.0

Published
26 March 2026
Modified
19 May 2026
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS Score 0.0022 13th percentile
Risk Priority 42 floored blend · peak EPSS

Summary

CVE-2026-0967 is a medium-severity Inefficient Regular Expression Complexity (CWE-1333) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

resource exhaustion, resulting in a Denial of Service (DoS) for the client.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-59844Same product: Libssh Libssh
CVE-2026-0968Same product: Libssh Libssh
CVE-2026-0965Same product: Libssh Libssh
CVE-2026-59849Same product: Libssh Libssh
CVE-2026-59843Same product: Libssh Libssh
CVE-2026-59848Same product: Libssh Libssh
CVE-2025-5351Same product: Libssh Libssh
CVE-2025-5318Same product: Libssh Libssh
CVE-2026-59851Same product: Libssh Libssh
CVE-2026-59842Same product: Libssh Libssh

Affected Assets

libssh
libssh
≤ 0.11.3
redhat
enterprise linux
10.0, 9.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover inefficient regex patterns via performance or static analysis.

Development standards and tools can require safe regex construction and forbid known exponential patterns.

Denial-of-service protections limit resource exhaustion caused by expensive regex evaluation.

Input validation can constrain data that would otherwise trigger worst-case regex complexity.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent inefficient regex via reviews, static analysis, and safe libraries.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover ReDoS issues in existing code but do not stop their introduction.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect and reject regex patterns with exponential worst-case complexity.

prevents

Secure development lifecycle mandates review of algorithmic efficiency, directly addressing ReDoS-prone regex.

prevents

Application security requirements can specify input-validation rules that limit regex complexity.

prevents

Secure architecture principles encourage avoidance of computationally expensive constructs such as catastrophic backtracking.

prevents

Secure coding standards explicitly prohibit or limit the use of inefficient regular expressions.

References