How severe is CVE-2026-84964?

CVE-2026-84964 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-84964 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-84964?

CVE-2026-84964 affects Mongodb C Driver. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-84964?

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

When was CVE-2026-84964 published?

CVE-2026-84964 was published on 2026-09-03 and last updated on 2026-09-22.

CVE-2026-84964

CVE-2026-84964 is a medium-severity vulnerability in Mongodb C Driver with a CVSS 3.x base score of 5.9. 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-415.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v4: 8.2
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-415
Affected product: Mongodb C Driver
Published: 2026-09-03
Last modified: 2026-09-22

Description

A double free in the OpenSSL-based TLS certificate revocation checking path of the MongoDB C Driver can be reached by a TLS endpoint that the client already trusts. During the handshake, specially formed certificate data can cause the same heap object to be released twice. An unauthenticated party acting as the trusted endpoint may cause the connecting client application to terminate unexpectedly.

Frequently asked questions

What is CVE-2026-84964?: A double free in the OpenSSL-based TLS certificate revocation checking path of the MongoDB C Driver can be reached by a TLS endpoint that the client already trusts. During the handshake, specially formed certificate data can cause the same heap object to be released twice. An unauthenticated party acting as the trusted endpoint may cause the connecting client application to terminate unexpectedly.
How severe is CVE-2026-84964?: CVE-2026-84964 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-84964 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-84964?: CVE-2026-84964 affects Mongodb C Driver. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-84964?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-84964 published?: CVE-2026-84964 was published on 2026-09-03 and last updated on 2026-09-22.

References

https://jira.mongodb.org/browse/CDRIVER-6409

Affected products (1)

cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*

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