Rpm: command execution via macro expansion in `rpmuncompress -x` for crafted `.gem` filenames
Summary
| CVE | CVE-2026-84233 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-01 15:17:43 UTC |
| Updated | 2026-09-04 02:17:19 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7 HIGH from [email protected]
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.001300000 probability, percentile 0.029500000 (date 2026-09-03)
Problem Types: CWE-78 | CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7 | HIGH | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 7 | HIGH | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Hardened Images | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-84233 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: This issue was discovered by Found by AISLE in partnership with Red Hat. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-05-18T03:32:25.000Z | Reported to Red Hat. |
| CNA | 2026-09-01T13:28:58.612Z | Made public. |
Workarounds
CNA: 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