CVE-2026-84838
Description
A flaw was found in rpmuncompress. This command injection vulnerability allows a local attacker to execute arbitrary commands. This occurs when rpmuncompress processes a specially crafted archive filename containing shell metacharacters, which are not properly escaped before being passed to shell command strings. Successful exploitation requires user interaction, where a user or automated workflow invokes rpmuncompress on the malicious file, leading to high impact on the confidentiality, integrity, and availability of data accessible to the invoking user.
Statement
This issue is considered Moderate severity because, although successful exploitation allows arbitrary command execution with the privileges of the user running rpmuncompress (or a build workflow that invokes it via %{__rpmuncompress}), exploitation requires a specially crafted local archive filename 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 issue, avoid processing untrusted archive filenames with `rpmuncompress` or any workflows that invoke `%{__rpmuncompress}`. Before any build or extraction steps, rename source and patch archives to remove any shell metacharacters from their filenames.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.8 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| 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:L/PR:N/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/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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