CVE-2026-91166 Vulnerability Analysis & Exploit Details

CVE-2026-91166
Vulnerability Scoring

5.7
/10
Significant Risk

Security assessments indicate that CVE-2026-91166 presents a notable risk, potentially requiring prompt mitigation.

Attack Complexity Details

  • Attack Complexity: High
    Exploits require significant effort and special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: High
    High-level privileges are required for exploitation.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: Required
    User interaction is necessary for successful exploitation.

CVE-2026-91166 Details

Status: Received on 21 Sep 2026, 19:17 UTC

Published on: 21 Sep 2026, 19:17 UTC

CVSS Release: version 3

CVSS3 Source

security-advisories@github.com

CVSS3 Type

Secondary

CVSS3 Vector

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

CVE-2026-91166 Vulnerability Summary

CVE-2026-91166: Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. From 0.25.0 until 0.27.6, the browser SSH path in warpgate-web-ssh/src/manager.rs handles RCEvent::HostKeyUnknown without the presenting hop identity and instead passes ssh_options.host and ssh_options.port for the final target to KnownHosts::trust. In Prompt and AutoAccept modes, a jump host key can therefore be stored for the target address. A machine later presenting the jump host key at the target address can be accepted as the target, allowing interception of user traffic and a newly issued certificate when certificate authentication is used. The native SSH path is unaffected because it tracks each hop separately. This issue is fixed in version 0.27.6.

Assessing the Risk of CVE-2026-91166

Access Complexity Graph

The exploitability of CVE-2026-91166 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2026-91166

The exploitability of CVE-2026-91166 is influenced by multiple factors. Security teams should analyze system configurations and apply appropriate countermeasures to mitigate threats.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2026-91166, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2026-91166, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: High
    Exploiting CVE-2026-91166 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: High
    CVE-2026-91166 could allow unauthorized modifications to data, potentially affecting system reliability and trust.
  • Availability: None
    CVE-2026-91166 does not impact system availability.

CVE-2026-91166 References

External References

CWE Common Weakness Enumeration

CWE-923

CAPEC Common Attack Pattern Enumeration and Classification

  • Infrastructure Manipulation CAPEC-161 An attacker exploits characteristics of the infrastructure of a network entity in order to perpetrate attacks or information gathering on network objects or effect a change in the ordinary information flow between network objects. Most often, this involves manipulation of the routing of network messages so, instead of arriving at their proper destination, they are directed towards an entity of the attackers' choosing, usually a server controlled by the attacker. The victim is often unaware that their messages are not being processed correctly. For example, a targeted client may believe they are connecting to their own bank but, in fact, be connecting to a Pharming site controlled by the attacker which then collects the user's login information in order to hijack the actual bank account.
  • Contradictory Destinations in Traffic Routing Schemes CAPEC-481 Adversaries can provide contradictory destinations when sending messages. Traffic is routed in networks using the domain names in various headers available at different levels of the OSI model. In a Content Delivery Network (CDN) multiple domains might be available, and if there are contradictory domain names provided it is possible to route traffic to an inappropriate destination. The technique, called Domain Fronting, involves using different domain names in the SNI field of the TLS header and the Host field of the HTTP header. An alternative technique, called Domainless Fronting, is similar, but the SNI field is left blank.
  • Android Activity Hijack CAPEC-501 An adversary intercepts an implicit intent sent to launch a Android-based trusted activity and instead launches a counterfeit activity in its place. The malicious activity is then used to mimic the trusted activity's user interface and prompt the target to enter sensitive data as if they were interacting with the trusted activity.
  • DHCP Spoofing CAPEC-697 An adversary masquerades as a legitimate Dynamic Host Configuration Protocol (DHCP) server by spoofing DHCP traffic, with the goal of redirecting network traffic or denying service to DHCP.

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