How severe is CVE-2026-93394?

CVE-2026-93394 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-93394 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-93394?

CVE-2026-93394 affects Mongodb C Driver. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-93394?

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

When was CVE-2026-93394 published?

CVE-2026-93394 was published on 2026-09-17 and last updated on 2026-09-25.

CVE-2026-93394

CVE-2026-93394 is a low-severity vulnerability in Mongodb C Driver with a CVSS 3.x base score of 3.7. 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-303.

Key facts

Severity: Low (CVSS 3.x base score 3.7)
CVSS v4: 6.3
EPSS exploit prediction: 0% (23rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-303
Affected product: Mongodb C Driver
Published: 2026-09-17
Last modified: 2026-09-25

Description

A flaw in libmongoc's SCRAM authentication implementation caused the client to continue the authentication handshake and transmit the client proof even when a nonce mismatch was detected in the server's first message. An unauthorized party with a man-in-the-middle position could exploit this by injecting a crafted server-first-message containing a controlled salt and low iteration count, then capturing the resulting client proof to perform offline password cracking. This vulnerability is mitigated by TLS, which is standard in production deployments.

Frequently asked questions

What is CVE-2026-93394?: A flaw in libmongoc's SCRAM authentication implementation caused the client to continue the authentication handshake and transmit the client proof even when a nonce mismatch was detected in the server's first message. An unauthorized party with a man-in-the-middle position could exploit this by injecting a crafted server-first-message containing a controlled salt and low iteration count, then capturing the resulting client proof to perform offline password cracking. This vulnerability is mitigated by TLS, which is standard in production deployments.
How severe is CVE-2026-93394?: CVE-2026-93394 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-93394 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-93394?: CVE-2026-93394 affects Mongodb C Driver. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-93394?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-93394 published?: CVE-2026-93394 was published on 2026-09-17 and last updated on 2026-09-25.

References

https://jira.mongodb.org/browse/CDRIVER-6315

Affected products (1)

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

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