CVE-2021-28855

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

0.90% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 56.9% of scored records. A rank, not a probability.

NVD base score

5.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

NVD analysis status

Modified. 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

2021-04-14 16:11Z5 YR AGO

Last updated

2026-01-26 16:23Z7 MO AGO

Reserved

2021-03-19

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-476NULL Pointer DereferenceBase

Data version

5.2

Document digest

f513432db941022c23bd3c55066b874d89661a6a4f16a5235e0bb7d04b6cb514

• fatihhcelik.github.iohttps://fatihhcelik.github.io/posts/NULL-Pointer-Dereference-Deark/
• github.comhttps://github.com/jsummers/deark/commit/287f5ac31dfdc074669182f51ece637706070eeb
• github.comhttps://github.com/fuzzing2026/CVE-PoCs/tree/main/deark-CVE-2021-28855