CVE-2026-0967: Inefficient Regular Expression Complexity in Red Hat Red Hat Enterprise Linux 10
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.
AI Analysis
Technical Summary
The vulnerability CVE-2026-0967 in libssh affects Red Hat Enterprise Linux 10 and involves inefficient regular expression processing in the match_pattern() function when handling crafted hostnames from client configuration or known_hosts files. This inefficient processing can cause excessive backtracking, leading to resource exhaustion and denial of service for the client application. The issue is rated with a low severity and a CVSS score of 2.2 (AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L). Red Hat has issued a security advisory (RHSA-2026:18160) providing an updated libssh package (version 0.12.0) that fixes this and other related vulnerabilities. The update is available for all supported architectures of Red Hat Enterprise Linux 10. The vendor advisory confirms the availability of an official fix and provides detailed instructions for applying the update.
Potential Impact
The impact of CVE-2026-0967 is limited to denial of service due to inefficient regular expression backtracking causing timeouts and resource exhaustion on the client side. There is no impact on confidentiality or integrity. The vulnerability requires local vector with high attack complexity and low privileges with user interaction. No known exploits in the wild have been reported. The overall severity is low as per the CVSS score of 2.2.
Mitigation Recommendations
An official security update from Red Hat is available that addresses this vulnerability by updating libssh to version 0.12.0. Users of Red Hat Enterprise Linux 10 should apply the update as described in the Red Hat advisory RHSA-2026:18160 and the referenced article https://access.redhat.com/articles/11258. Applying this update will remediate the denial of service issue caused by inefficient regular expression processing. No additional mitigation steps are required beyond applying the official patch.
CVE-2026-0967: Inefficient Regular Expression Complexity in Red Hat Red Hat Enterprise Linux 10
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.
CVSS v3.0
Score 2.2low
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-0967 in libssh affects Red Hat Enterprise Linux 10 and involves inefficient regular expression processing in the match_pattern() function when handling crafted hostnames from client configuration or known_hosts files. This inefficient processing can cause excessive backtracking, leading to resource exhaustion and denial of service for the client application. The issue is rated with a low severity and a CVSS score of 2.2 (AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L). Red Hat has issued a security advisory (RHSA-2026:18160) providing an updated libssh package (version 0.12.0) that fixes this and other related vulnerabilities. The update is available for all supported architectures of Red Hat Enterprise Linux 10. The vendor advisory confirms the availability of an official fix and provides detailed instructions for applying the update.
Potential Impact
The impact of CVE-2026-0967 is limited to denial of service due to inefficient regular expression backtracking causing timeouts and resource exhaustion on the client side. There is no impact on confidentiality or integrity. The vulnerability requires local vector with high attack complexity and low privileges with user interaction. No known exploits in the wild have been reported. The overall severity is low as per the CVSS score of 2.2.
Mitigation Recommendations
An official security update from Red Hat is available that addresses this vulnerability by updating libssh to version 0.12.0. Users of Red Hat Enterprise Linux 10 should apply the update as described in the Red Hat advisory RHSA-2026:18160 and the referenced article https://access.redhat.com/articles/11258. Applying this update will remediate the denial of service issue caused by inefficient regular expression processing. No additional mitigation steps are required beyond applying the official patch.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- redhat
- Date Reserved
- 2026-01-14T21:55:01.348Z
- Cvss Version
- 3.0
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-0967","vendor":"Red Hat"}]
Threat ID: 69c5a54c3c064ed76fcfc863
Added to database: 03/26/2026, 21:29:48 UTC
Last enriched: 05/19/2026, 18:04:10 UTC
Last updated: 07/31/2026, 19:22:57 UTC
Views: 106
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