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Fencer Vulns
medium 5.5

CVE-2026-6862 json

Efivar: efivar: denial of service due to stack overflow in device path node parsing

published 2026-04-22 6 mo ago modified 2026-11-05 3 d ago also EUVD-2026-24957

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits
0
none known

Summary

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).

Patch / fix

  • Red Hat Red Hat Hardened Images 39-13.1.hum1
  • efivar hummingbird 1 39-13.1.hum1
  • efivar-libs hummingbird 1 39-13.1.hum1

red hat advisories RHSA-2026:69321

  • efivar openSUSE Tumbleweed 39-1.1

opensuse advisories openSUSE-SU-2026:12378-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-6862 updated cvss 5.5

efivar: efivar: Denial of Service due to stack overflow in device path node parsing

  • Red Hat Enterprise Linux 7 efivar, efivar-libs Red Hat Enterprise Linux 8 efivar, efivar-libs Red Hat Enterprise Linux 9 efivar, efivar-libs Red Hat Enterprise Linux 10 efivar Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    under investigation
  • Red Hat Hardened Images efivar 39-13.1.hum1, efivar-libs 39-13.1.hum1
    fixed: vendor fix RHSA-2026:69321

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected products

  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.