What is CVE-2021-39877?

CVE-2021-39877 is a high-severity vulnerability in GitLab, classified under Uncontrolled Resource Consumption. CVSS score: 7.7/10. Published 2021-10-04.

How severe is CVE-2021-39877?

High severity. CVSS v3 base score is 7.7 out of 10.

Resource exhaustion in GitLab

CVE-2021-39877

A vulnerability was discovered in GitLab starting with version 12.2 that allows an attacker to cause uncontrolled resource consumption with a specially crafted file.

Vulnerability class: DoS (Denial of Service)

Published 2021-10-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.010 (62.7th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 62.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

GitLab — versions >=12.2, <14.1.7, >=14.2, <14.2.5, >=14.3, <14.3.1

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

gitlab.com/gitlab-org/gitlab/-/issues/300095 (Broken Link)
hackerone.com/reports/1077021 (Permissions Required, Third Party Advisory)
gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39877.json (Vendor Advisory)

Frequently asked questions

What is CVE-2021-39877?: CVE-2021-39877 is a high-severity vulnerability in GitLab, classified under Uncontrolled Resource Consumption. CVSS score: 7.7/10. Published 2021-10-04.
How severe is CVE-2021-39877?: High severity. CVSS v3 base score is 7.7 out of 10.