CVE-2021-34534

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

2.24% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 82.7% of scored records. A rank, not a probability.

NVD base score

6.8 (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:U/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

2021-08-12 18:12Z5 YR AGO

Last updated

2026-08-10 15:09Z2 MO AGO

Reserved

2021-06-09

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

Medium (CVSS 6.8)

CNA CVSS vector

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

Weaknesses

No CWE assigned

Data version

5.2

Document digest

fe85320b70639f864ab52c32d4b9a09f40710e6c3c9e28c2385aa1a44d4c06ba

• msrc.microsoft.comWindows MSHTML Platform Remote Code Execution Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34534vendor-advisorypatch
• portal.msrc.microsoft.comhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34534x_refsource_MISC