Cyber Resilience

CVE-2026-6862

DoS in Ubuntu Libefiboot

Published
22 April 2026
Modified
13 May 2026
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS Score 0.0010 1th percentile
Risk Priority 40 floored blend · peak EPSS

Summary

CVE-2026-6862 is a medium-severity Uncontrolled Recursion (CWE-674) vulnerability in Ubuntu Libefiboot. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

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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).

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-0994Shared CWE-674
CVE-2024-47831Shared CWE-674
CVE-2025-7005Shared CWE-674
CVE-2026-48506Shared CWE-674
CVE-2026-49847Shared CWE-674
CVE-2026-63759Shared CWE-674
CVE-2024-58103Shared CWE-674
CVE-2025-10728Shared CWE-674
CVE-2024-42369Shared CWE-674
CVE-2023-53655Shared CWE-674

Affected Assets

ubuntu
libefiboot
all versions

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Input validation can reject or constrain data that would otherwise drive unbounded recursive calls.

DoS protection mechanisms limit the resource-exhaustion impact of uncontrolled recursion without eliminating the flaw.

System monitoring can observe anomalous resource consumption that signals runaway recursion after it begins.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent coding errors such as missing recursion limits or termination conditions.

DE.CM-09 partial match
prevents

Runtime monitoring of compute resources can detect excessive consumption caused by uncontrolled recursion.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record uncontrolled recursion flaws before deployment.

PR.IR-04 partial match
prevents

Capacity monitoring and resource provisioning can absorb or limit the impact of runaway recursion.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development can detect excessive recursion via static analysis or fuzzing.

prevents

Secure development life cycle requires controls that prevent uncontrolled recursion through design and code review.

prevents

Application security requirements can mandate recursion limits or stack-depth checks.

prevents

Secure system architecture principles include resource-management and input-validation rules that limit recursion.

prevents

Secure coding standards directly prohibit or constrain recursive constructs that could exhaust stack or memory.

finds

Capacity management includes monitoring and limits that mitigate resource exhaustion from runaway recursion.

References