CVE-2021-28363

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

2.16% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 81.9% 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:N/S:U/C:L/I:L/A:N

NVD analysis status

Modified. NVD last modified this record on 2026-10-14.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

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

2021-03-15 00:00Z5 YR AGO

Last updated

2026-10-14 11:39Z15 DAYS AGO

Reserved

2021-03-13

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-295Improper Certificate ValidationBase

Data version

5.2

Document digest

00bc9576ccad875e68739d3db59cb580c13fdbdde6dbd2e5bbeb05649432f06f

• github.comhttps://github.com/urllib3/urllib3/commits/main
• lists.fedoraproject.orgFEDORA-2021-3f378dda90https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4S65ZQVZ2ODGB52IC7VJDBUK4M5INCXL/vendor-advisory
• security.gentoo.orgGLSA-202107-36https://security.gentoo.org/glsa/202107-36vendor-advisory
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuoct2021.html
• pypi.orghttps://pypi.org/project/urllib3/1.26.4/
• github.comhttps://github.com/urllib3/urllib3/commit/8d65ea1ecf6e2cdc27d42124e587c1b83a3118b0
• github.comhttps://github.com/urllib3/urllib3/security/advisories/GHSA-5phf-pp7p-vc2r
• security.gentoo.orgGLSA-202305-02https://security.gentoo.org/glsa/202305-02vendor-advisory
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20240621-0007/
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-398330.html