How severe is CVE-2026-81518?

CVE-2026-81518 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-81518 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-81518?

CVE-2026-81518 affects Mongodb Bi Connector. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-81518?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-81518 published?

CVE-2026-81518 was published on 2026-08-28 and last updated on 2026-09-29.

CVE-2026-81518

CVE-2026-81518 is a high-severity vulnerability in Mongodb Bi Connector with a CVSS 3.x base score of 7.5. 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-295.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Mongodb Bi Connector
Published: 2026-08-28
Last modified: 2026-09-29

Description

When mongosqld is configured with a client certificate authority file, the listener requests a client certificate during the TLS handshake but does not require one, so a client that presents no certificate is still accepted. In deployments that rely on client certificates as the sole means of identifying users, a remote party with network access to the listener can therefore establish a session and read the MongoDB data exposed through the connector.

Frequently asked questions

What is CVE-2026-81518?: When mongosqld is configured with a client certificate authority file, the listener requests a client certificate during the TLS handshake but does not require one, so a client that presents no certificate is still accepted. In deployments that rely on client certificates as the sole means of identifying users, a remote party with network access to the listener can therefore establish a session and read the MongoDB data exposed through the connector.
How severe is CVE-2026-81518?: CVE-2026-81518 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-81518 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-81518?: CVE-2026-81518 affects Mongodb Bi Connector. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-81518?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-81518 published?: CVE-2026-81518 was published on 2026-08-28 and last updated on 2026-09-29.

References

https://www.mongodb.com/docs/bi-connector/current/release-notes/

Affected products (1)

cpe:2.3:a:mongodb:bi_connector:*:*:*:*:*:*:*:*

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