CVE-2021-34446

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

2.04% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 81.0% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-08-10.

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

2021-07-16 20:19Z5 YR AGO

Last updated

2026-08-10 15:11Z2 MO AGO

Reserved

2021-06-09

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

High (CVSS 8.0)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C

Weaknesses

No CWE assigned

Data version

5.2

Document digest

d68edb8f458e983205a66852de629b5a0c88fdc41d5a9c2f9b9b711b8aeccb3b

• msrc.microsoft.comWindows HTML Platforms Security Feature Bypass Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34446vendor-advisorypatch
• portal.msrc.microsoft.comhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34446x_refsource_MISC