CVE-2026-84233
Description
A flaw was found in rpm. A local attacker could supply a specially crafted .gem filename containing RPM macro syntax. When a user or automated workflow invokes rpmuncompress -x on this file, the macro expansion occurs during command construction. This allows the attacker to execute arbitrary commands with the privileges of the invoking account, leading to a compromise of confidentiality, integrity, and availability.
Statement
This issue is considered Moderate severity because, although successful exploitation allows arbitrary command execution with the privileges of the user or workflow invoking rpmuncompress -x (or a build workflow that invokes it via %{__rpmuncompress}), exploitation requires a specially crafted local .gem filename containing RPM macro syntax to be processed by that tool. The vulnerable code is not exposed as a network service and cannot be triggered remotely without a user or automated workflow invoking rpmuncompress on the attacker-controlled filename.
Mitigation
To mitigate this vulnerability, avoid using `rpmuncompress -x` (or a build workflow that invokes it via %{__rpmuncompress}) on `.gem` files from untrusted sources. Before extraction, rename `.gem` files to remove any RPM macro syntax (e.g., `%(...)`) or utilize an alternative extraction tool that does not expand RPM macros in filenames. In automated environments, implement validation to reject or sanitize untrusted archive names prior to processing
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7 | N/A | 7 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Non-Repudiation
Technical Impact: Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart; Read Files or Directories; Modify Files or Directories; Read Application Data; Modify Application Data; Hide Activities
Attackers could execute unauthorized operating system commands, which could then be used to disable the product, or read and modify data for which the attacker does not have permissions to access directly. Since the targeted application is directly executing the commands instead of the attacker, any malicious activities may appear to come from the application or the application's owner.
Acknowledgements
This issue was discovered by Found by AISLE in partnership with Red Hat.
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