What is CVE-2021-36377?

CVE-2021-36377 is a high-severity vulnerability in Fossil-Scm Fossil, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2021-07-12.

How severe is CVE-2021-36377?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Fossil-Scm Fossil

CVE-2021-36377

Fossil before 2.14.2 and 2.15.x before 2.15.2 often skips the hostname check during TLS certificate validation.

Vulnerability class: Improper Certificate Validation

Published 2021-07-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.006 (45.4th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Fossil-Scm Fossil
Fedoraproject Fedora — versions 34

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

fossil-scm.org/forum/forumpost/8d367e16f53d93c789d70bd3bf2c9587227bbd5c6a7b8e51… (Vendor Advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)

Frequently asked questions

What is CVE-2021-36377?: CVE-2021-36377 is a high-severity vulnerability in Fossil-Scm Fossil, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2021-07-12.
How severe is CVE-2021-36377?: High severity. CVSS v3 base score is 7.5 out of 10.