How severe is CVE-2021-31158?

CVE-2021-31158 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 high, integrity none, and availability none.

Is CVE-2021-31158 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31158?

CVE-2021-31158 affects Couchbase Couchbase Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-31158?

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

When was CVE-2021-31158 published?

CVE-2021-31158 was published on 2021-05-19 and last updated on 2026-06-17.

CVE-2021-31158

CVE-2021-31158 is a medium-severity vulnerability in Couchbase Couchbase Server 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-863.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Couchbase Couchbase Server
Published: 2021-05-19
Last modified: 2026-06-17

Description

In the Query Engine in Couchbase Server 6.5.x and 6.6.x through 6.6.1, Common Table Expression queries were not correctly checking the user's permissions, allowing read-access to resources beyond what those users were explicitly allowed to access.

Frequently asked questions

What is CVE-2021-31158?: In the Query Engine in Couchbase Server 6.5.x and 6.6.x through 6.6.1, Common Table Expression queries were not correctly checking the user's permissions, allowing read-access to resources beyond what those users were explicitly allowed to access.
How severe is CVE-2021-31158?: CVE-2021-31158 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 high, integrity none, and availability none.
Is CVE-2021-31158 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31158?: CVE-2021-31158 affects Couchbase Couchbase Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-31158?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-31158 published?: CVE-2021-31158 was published on 2021-05-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:couchbase:couchbase_server:*:*:*:*:*:*:*:*

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