CVE-2021-21391

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

1.67% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 74.7% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

CVSS:3.1/AV:N/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

2021-04-29 00:20Z5 YR AGO

Last updated

2024-08-03 18:09Z2 YR AGO

Reserved

2020-12-22

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Medium (CVSS 6.5)

CNA CVSS vector

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

Weaknesses

• CWE-400Uncontrolled Resource ConsumptionClass

Data version

5.1

Document digest

4e617537f55f28ff185f7a965ad4ca8d6ab4c45b06b2c72ed892db8574b052fd

• www.npmjs.comhttps://www.npmjs.com/package/%40ckeditor/ckeditor5-markdown-gfmx_refsource_MISC
• github.comhttps://github.com/ckeditor/ckeditor5/security/advisories/GHSA-3rh3-wfr4-76mjx_refsource_CONFIRM
• www.npmjs.comhttps://www.npmjs.com/package/%40ckeditor/ckeditor5-enginex_refsource_MISC
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