How severe is CVE-2021-39939?

CVE-2021-39939 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-39939 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39939?

CVE-2021-39939 primarily affects Gitlab. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-39939?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-39939 published?

CVE-2021-39939 was published on 2021-12-13 and last updated on 2026-06-17.

CVE-2021-39939

CVE-2021-39939 is a medium-severity vulnerability in Gitlab with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Gitlab
Published: 2021-12-13
Last modified: 2026-06-17

Description

An uncontrolled resource consumption vulnerability in GitLab Runner affecting all versions starting from 13.7 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2, allows an attacker triggering a job with a specially crafted docker image to exhaust resources on runner manager

Frequently asked questions

What is CVE-2021-39939?: An uncontrolled resource consumption vulnerability in GitLab Runner affecting all versions starting from 13.7 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2, allows an attacker triggering a job with a specially crafted docker image to exhaust resources on runner manager
How severe is CVE-2021-39939?: CVE-2021-39939 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-39939 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39939?: CVE-2021-39939 primarily affects Gitlab. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-39939?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-39939 published?: CVE-2021-39939 was published on 2021-12-13 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*

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