CVE-2026-21427

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.18% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 7.7% of scored records. A rank, not a probability.

NVD base score

8.5 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-01-08 04:12Z9 MO AGO

Last updated

2026-01-22 07:03Z9 MO AGO

Reserved

2025-12-25

Assigning CNA

jpcert

Record state

PUBLISHED

Severity

High (CVSS 8.5)

CNA CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-427Uncontrolled Search Path ElementBase

Data version

5.2

Document digest

5cc29d4c3341839be44bfd99b9c9b1ba3429aa527b52a5050a8f56e06ed89c7c

• jpn.pioneerhttps://jpn.pioneer/ja/support/software/stellanova/dac_driver/
• jvn.jphttps://jvn.jp/en/jp/JVN17956874/