How severe is CVE-2021-39947?

CVE-2021-39947 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-39947 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39947?

CVE-2021-39947 affects Gitlab Gitlab Runner. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-39947?

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

When was CVE-2021-39947 published?

CVE-2021-39947 was published on 2022-06-06 and last updated on 2026-06-17.

CVE-2021-39947

CVE-2021-39947 is a medium-severity vulnerability in Gitlab Gitlab Runner with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Gitlab Gitlab Runner
Published: 2022-06-06
Last modified: 2026-06-17

Description

In specific circumstances, trace file buffers in GitLab Runner versions up to 14.3.4, 14.4 to 14.4.2, and 14.5 to 14.5.2 would re-use the file descriptor 0 for multiple traces and mix the output of several jobs

Frequently asked questions

What is CVE-2021-39947?: In specific circumstances, trace file buffers in GitLab Runner versions up to 14.3.4, 14.4 to 14.4.2, and 14.5 to 14.5.2 would re-use the file descriptor 0 for multiple traces and mix the output of several jobs
How severe is CVE-2021-39947?: CVE-2021-39947 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-39947 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39947?: CVE-2021-39947 affects Gitlab Gitlab Runner. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-39947?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-39947 published?: CVE-2021-39947 was published on 2022-06-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:gitlab:gitlab_runner:*:*:*:*:*:*:*:*