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Full vulnerability report · 2026
CVE-2026-81530High confidence

KMS master key exposure via unredacted credential serialization in driver settings string

MongoDB · C# Driver

6.8MediumCVSS 4.0
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Low, lowered one band.downgradedsince 27 Aug 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.09% for the current model date.

Compensating controls

  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs MongoDB C# Driver and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-67214

No EUVD known-exploited evidence

A weakness in the client-side encryption configuration surface of the MongoDB C# Driver causes sensitive key-management credential material supplied by the application to be reproduced verbatim in the driver's human-readable diagnostic representation of its client settings, instead of being masked as other secret fields are. A party able to read the application's logs, diagnostic output, or a process memory dump may thereby recover the plaintext credentials and use them to decrypt protected field data.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
6.8 · CVSS 4.0
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified
01

What, why and how

A weakness in the client-side encryption configuration surface of the MongoDB C# Driver causes sensitive key-management credential material supplied by the application to be reproduced verbatim in the driver's human-readable diagnostic representation of its client settings, instead of being masked as other secret fields are. A party able to read the application's logs, diagnostic output, or a process memory dump may thereby recover the plaintext credentials and use them to decrypt protected field data.

What

A weakness in the client-side encryption configuration surface of the MongoDB C# Driver causes sensitive key-management credential material supplied by the application to be reproduced verbatim in the driver's human-readable diagnostic representation of its client settings, instead of being masked as other secret fields are. A party able to read the application's logs, diagnostic output, or a process memory dump may thereby recover the plaintext credentials and use them to decrypt protected field data.

Why

The product writes sensitive information to a log file.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

A weakness in the client-side encryption configuration surface of the MongoDB C# Driver causes sensitive key-management credential material supplied by the application to be reproduced verbatim in the driver's human-readable diagnostic representation of its client settings, instead of being masked as other secret fields are. A party able to read the application's logs, diagnostic output, or a process memory dump may thereby recover the plaintext credentials and use them to decrypt protected field data.

Why

The product writes sensitive information to a log file.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Insertion of Sensitive Information into Log File → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-532 ↗

CWE-532: Insertion of Sensitive Information into Log File. The product writes sensitive information to a log file.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
CWE-532
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-67214Official EUVD mapping

A weakness in the client-side encryption configuration surface of the MongoDB C# Driver causes sensitive key-management credential material supplied by the application to be reproduced verbatim in the driver's human-readable diagnostic representation of its client settings, instead of being masked as other secret fields are. A party able to read the application's logs, diagnostic output, or a process memory dump may thereby recover the plaintext credentials and use them to decrypt protected field data.

Official EUVD record ↗
BSI · German · WID-SEC-2026-3066MongoDB Clients: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in verschiedenen MongoDB Clients ausnutzen, um Sicherheitsvorkehrungen zu umgehen, vertrauliche Informationen offenzulegen, Daten zu manipulieren oder Denial-of-Service-Zustände herbeizuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260902Security Bulletin 2 Sept 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 2 Sept 2026, published on 2 September 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-036018MongoDB Inc.のMongoDB C# Driverにおけるログファイルからの情報漏えいに関する脆弱性

MongoDB C#ドライバーのクライアント側暗号化設定インターフェースに脆弱性があり、アプリケーションから提供された機密性の高いキー管理認証情報が、他の秘密フィールドとは異なりマスクされず、そのままドライバーの人間が読みやすい診断用クライアント設定表現に再現されてしまいます。そのため、アプリケーションのログ、診断出力、またはプロセスメモリダンプを読み取ることができる第三者が平文の認証情報を回収し、それを用いて保護されたフィールドデータを復号化する可能性があります。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
C# Driver: 2.10.0 < 3.11.1
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 27 Aug 2026 · Last source change 28 Aug 2026, 15:44 UTC · CWE-532 · Insertion of Sensitive Information into Log File

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-28
European sourceENISA EUVD · EUVD-2026-67214
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: jira.mongodb.org/CSHARP-6164.
    Before
    no authoritative guidance recorded
    After
    vendor advisory: jira.mongodb.org/CSHARP-6164
    cna@mongodb.com ↗
  2. Affected versionsThe structured affected or fixed version information changed.
    Before
    2.10.0 < 3.11.1 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    C# Driver: 2.10.0 < 3.11.1 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  3. ENISA EUVD mappingEUVD-2026-67214 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-67214"}
    ENISA EUVD ↗
  4. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
  5. CVSS scoreCVSS vector changed while the displayed base score remained 6.8.
    Before
    6.8 (CVSS 4.0 · CNA · CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/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)
    After
    6.8 (CVSS 4.0 · CNA · CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N)
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-67214↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-81530 · cve.blacktree.nl