How severe is CVE-2021-43979?

CVE-2021-43979 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-43979 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43979?

CVE-2021-43979 affects Openpolicyagent Gatekeeper. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43979?

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

When was CVE-2021-43979 published?

CVE-2021-43979 was published on 2021-11-17 and last updated on 2026-06-17.

CVE-2021-43979

CVE-2021-43979 is a medium-severity vulnerability in Openpolicyagent Gatekeeper 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. The underlying weakness is classified as CWE-670.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-670
Affected product: Openpolicyagent Gatekeeper
Published: 2021-11-17
Last modified: 2026-06-17

Description

Styra Open Policy Agent (OPA) Gatekeeper through 3.7.0 mishandles concurrency, sometimes resulting in incorrect access control. The data replication mechanism allows policies to access the Kubernetes cluster state. During data replication, OPA/Gatekeeper does not wait for the replication to finish before processing a request, which might cause inconsistencies between the replicated resources in OPA/Gatekeeper and the resources actually present in the cluster. Inconsistency can later be reflected in a policy bypass. NOTE: the vendor disagrees that this is a vulnerability, because Kubernetes states are only eventually consistent

Frequently asked questions

What is CVE-2021-43979?: Styra Open Policy Agent (OPA) Gatekeeper through 3.7.0 mishandles concurrency, sometimes resulting in incorrect access control. The data replication mechanism allows policies to access the Kubernetes cluster state. During data replication, OPA/Gatekeeper does not wait for the replication to finish before processing a request, which might cause inconsistencies between the replicated resources in OPA/Gatekeeper and the resources actually present in the cluster. Inconsistency can later be reflected in a policy bypass. NOTE: the vendor disagrees that this is a vulnerability, because Kubernetes states are only eventually consistent
How severe is CVE-2021-43979?: CVE-2021-43979 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-43979 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43979?: CVE-2021-43979 affects Openpolicyagent Gatekeeper. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43979?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-43979 published?: CVE-2021-43979 was published on 2021-11-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:openpolicyagent:gatekeeper:*:*:*:*:*:*:*:*

Other CWE-670 vulnerabilities

CVE-2025-43359 — Critical (CVSS 9.8): A logic issue was addressed with improved state management. This issue is fixed in iOS 18.7 and iPadOS 18.7, iOS 26 and…
CVE-2022-25745 — Critical (CVSS 9.8): Memory corruption in modem due to improper input validation while handling the incoming CoAP message
CVE-2020-1914 — Critical (CVSS 9.8): A logic vulnerability when handling the SaveGeneratorLong instruction in Facebook Hermes prior to commit…
CVE-2020-17466 — Critical (CVSS 9.8): Turcom TRCwifiZone through 2020-08-10 allows authentication bypass by visiting manage/control.php and ignoring 302…
CVE-2019-17192 — Critical (CVSS 9.8): The WebRTC component in the Signal Private Messenger application through 4.47.7 for Android processes videoconferencing…
CVE-2026-55276 — Critical (CVSS 9.1): Always-Incorrect Control Flow Implementation vulnerability in Apache Tomcat meant that special roles and empty…

Browse all CWE-670 vulnerabilities →