Quick answers
- Is CVE-2026-126838 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-126838 being exploited in the wild.
- How severe is CVE-2026-126838?
- Medium severity, with a CVSS score of 5.5, published 12 November 2026.
- Which products and versions are affected?
- MongoDB Rust Driver.
- Is there a fix for CVE-2026-126838?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-126838 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-126838?
- Check whether you run MongoDB Rust Driver. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The client-side field level encryption (CSFLE) settings component in MongoDB Rust Driver improperly includes key management service (KMS) credentials in its diagnostic formatting output without sanitization. An attacker with local read access to application logs or diagnostic output can extract unencrypted KMS credential material, potentially allowing unauthorized access to the key management infrastructure or decryption of field-level encrypted data.
Affected products
- MongoDB Rust Driver
Timeline
- 2026-11-12: disclosed