Efivar: efivar: denial of service due to stack overflow in device path node parsing
Summary
| CVE | CVE-2026-6862 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-22 14:17:08 UTC |
| Updated | 2026-05-13 16:36:49 UTC |
| Description | A flaw was found in libefiboot, a component of efivar. The device path node parser in libefiboot fails to validate that each node's Length field is at least 4 bytes, which is the minimum size for an EFI (Extensible Firmware Interface) device path node header. A local user could exploit this vulnerability by providing a specially crafted device path node. This can lead to infinite recursion, causing stack exhaustion and a process crash, resulting in a denial of service (DoS). |
Risk And Classification
Primary CVSS: v3.1 5.5 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Problem Types: CWE-674 | CWE-674 Uncontrolled Recursion
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Ubuntu | Libefiboot | - | All | All | All |
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 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 OpenShift Container Platform 4 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-6862 | [email protected] | access.redhat.com | Third Party Advisory |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | Issue Tracking, Third Party Advisory |
| 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: Red Hat would like to thank Mathis Huron (Oteria Cyber School, FuzzingLabs) for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-04-09T00:00:00.000Z | Reported to Red Hat. |
| CNA | 2026-04-09T00:00:00.000Z | Made public. |
Workarounds
CNA: Applications using efi_loadopt_is_valid() should validate the size of the input buffer before passing it to libefiboot. As a library-level fix, the device path iterator should enforce a minimum node Length of 4 before recursing: if (dp->length < 4) return -1;
There are currently no legacy QID mappings associated with this CVE.