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CVE.org (no NVD analysis yet)· CNA mongodb

CVE-2026-126838: Rust Driver public Client Debug output exposes CSFLE KMS master-key material

MediumCVSS 5.7 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: MongoDB Rust Driver 2.6.1, 2.7.1, 2.8.2.

Low priority for now. Upgrade to MongoDB Rust Driver 2.6.1, 2.7.1, 2.8.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org

A MongoDB Rust Driver component that holds client-side field level encryption settings includes key management service credential material in its diagnostic formatting output without redaction. An application that records or displays this formatted output may place that material where a party with read access to the application's diagnostic output can see it, which may result in unintended disclosure of key material.

Published
Nov 12, 2026
Updated
Nov 12, 2026
EPSS
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · —

CNA vs NVD score

NVD
—
CNA · mongodb
5.7
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-126838

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (mongodb). Independent of NVD's CPE analysis and usually ahead of it.

  • MongoDB Rust Driver

    • 3.7.0, 3.6.0, 3.3.0, 2.5.0, 2.4.0affected
    • 3.9.0 and later · before 3.9.1affected · semver
    • 3.8.0 and later · before 3.8.2affected · semver
    • 3.5.0 and later · before 3.5.2affected · semver
    • 3.4.0 and later · before 3.4.1affected · semver
    • 3.2.0 and later · before 3.2.5affected · semver
    • 3.1.0 and later · before 3.1.1affected · semver
    • 3.0.0 and later · before 3.0.1affected · semver
    • 2.8.0 and later · before 2.8.2affected · semver
    • 2.7.0 and later · before 2.7.1affected · semver

Same product

mongodb: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-11695Configuration may unexpectedly disable certificate validation
    30Monitor
  • CVE-2024-6382Adversarial unsanitized input may cause MongoDB Rust Driver to issue unintended commands.
    30Monitor
  • CVE-2026-81526Cross-database write redirection via unvalidated dotted database name in bulk write namespaces
    28Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2021-20332Aug 2, 2021 · MongoDB Rust Driver may publish events containing authentication-related data to a connection pool event listener configured by an application
    17Monitor
  • ← EarlierCVE-2026-88024Sep 10, 2026 · GridFS data disclosure and deletion via query-operator injection in file IDs in the MongoDB Rust Driver
    24Monitor
  • ← EarlierCVE-2026-120673Nov 3, 2026 · Rust Driver 3.9.1 exports CSFLE plaintext in `db.query.text` before encrypting the command
    27Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
MongoDB Rust Driver2.6.1Vendor (CNA)
MongoDB Rust Driver2.7.1Vendor (CNA)
MongoDB Rust Driver2.8.2Vendor (CNA)
MongoDB Rust Driver3.0.1Vendor (CNA)
MongoDB Rust Driver3.1.1Vendor (CNA)
MongoDB Rust Driver3.2.5Vendor (CNA)
MongoDB Rust Driver3.4.1Vendor (CNA)
MongoDB Rust Driver3.5.2Vendor (CNA)
MongoDB Rust Driver3.8.2Vendor (CNA)
MongoDB Rust Driver3.9.1Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 13, 2026+1 d

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-1206739 days apartRust Driver 3.9.1 exports CSFLE plaintext in `db.query.text` before encrypting the command
    27Monitor

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
X

Weakness class (CWE)

CWE-532 · Insertion of Sensitive Information into Log File

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records