CVE-2021-23976

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

1.10% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 63.4% of scored records. A rank, not a probability.

NVD base score

8.1 (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:H/I:H/A:N

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

2021-02-26 01:48Z5 YR AGO

Last updated

2024-08-03 19:14Z2 YR AGO

Reserved

2021-01-13

Assigning CNA

mozilla

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-1021Improper Restriction of Rendered UI Layers or FramesBase

Data version

5.1

Document digest

eff8f280e140418b70aade7035dfbb37c498c523ce9fbcb0cd1f779e1529cd1b

• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2021-07/x_refsource_MISC
• bugzilla.mozilla.orghttps://bugzilla.mozilla.org/show_bug.cgi?id=1684627x_refsource_MISC
• security.gentoo.orgGLSA-202104-10https://security.gentoo.org/glsa/202104-10vendor-advisoryx_refsource_GENTOO