Skip to main content

libmongocrypt EUVDEUVD-2026-70507

| CVE-2026-84971 HIGH
Reachable Assertion (CWE-617)
2026-09-03 cna@mongodb.com GHSA-pxxc-vwf4-r3mr
7.1
CVSS 4.0 · Vendor: mongodb
Share

Severity by source

Vendor (mongodb) PRIMARY
7.1 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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
vuln.today AI
6.5 MEDIUM

Network-reachable via crafted ciphertext with low-privilege write access required; pure availability impact (process termination); no confidentiality or integrity loss.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (mongodb).

CVSS VectorVendor: mongodb

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
X

Lifecycle Timeline

4
Patch available
Sep 03, 2026 - 16:01 EUVD
Metadata Corrected
Sep 03, 2026 - 15:40 vuln.today
tag: Information Disclosure replaced by Denial Of Service
Analysis Generated
Sep 03, 2026 - 15:32 vuln.today
CVE Published
Sep 03, 2026 - 15:17 cve.org
HIGH 7.1

DescriptionCVE.org

Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control the responses the application receives, may cause that application to stop running.

AnalysisAI

Process-terminating denial of service in libmongocrypt's decryption path allows a low-privileged attacker to crash applications using MongoDB Client-Side Field Level Encryption (CSFLE). Tracked as MONGOCRYPT-971, the vulnerability is triggered when an unexpected-size encrypted value reaches the decryption routine, firing a reachable assertion (CWE-617) that abruptly terminates the host process rather than returning a handled error. …

Unlock full vulnerability intelligence

  • Risk assessment & exploitation conditions
  • Attack chain visualization
  • Remediation with exact patch versions
  • Threat intelligence from 22 sources
  • Personal watchlist & email alerts

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
technique details hidden
Delivery
technique details hidden
Exploit
technique details hidden
Execution
technique details hidden
Persist
technique details hidden
Impact
technique details hidden

Vulnerability AssessmentAI

Exploitation Exploitation requires the target application to have MongoDB Client-Side Field Level Encryption (CSFLE) explicitly enabled and to use libmongocrypt for field decryption - deployments not using CSFLE are entirely unaffected. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The CVSS 4.0 base score of 7.1 (AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H) accurately reflects an availability-only DoS with low complexity but a low-privilege prerequisite. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario Full exploit scenario with step-by-step reproduction available after sign-in.
Remediation Upgrade libmongocrypt to the fixed version once MongoDB publishes it via MONGOCRYPT-971 (https://jira.mongodb.org/browse/MONGOCRYPT-971); no exact patched version is confirmed in the available data, so the Jira ticket and the mongodb/libmongocrypt GitHub release page should be monitored directly. … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 24 hours: Deploy automated dependency scanning to identify all systems using libmongocrypt and implement real-time alerting for unexpected application crashes or restarts. …

Sign in for detailed remediation steps and compensating controls.

Threat intelligence, references, and detailed analysis are available after sign-in.

Share

EUVD-2026-70507 vulnerability details – vuln.today

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy