Cyber Resilience

CVE-2026-81522

Mongodb C\+\+ Driver 3.0.0 – 4.5.2

Published
27 August 2026
Modified
29 September 2026
Patch / advisory
CVSS Score v4 8.6
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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
EPSS Score 0.0045 37th percentile
Risk Priority 39 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-81522 is a high-severity Improper Encoding or Escaping of Output (CWE-116) vulnerability in Mongodb C\+\+ Driver. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 37th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A weakness in the MongoDB C++ Driver's handling of caller-supplied namespace identifiers allows special characters embedded in those identifiers. An application that builds a namespace identifier from untrusted input without validating it may therefore have its operation directed at a…

more

different target than intended. This can result in limited unauthorized read and write access to data belonging to another logical tenant of the affected application.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-23599Shared CWE-116
CVE-2025-11712Shared CWE-116
CVE-2025-32072Shared CWE-116
CVE-2023-40014Shared CWE-116
CVE-2026-40023Shared CWE-116
CVE-2026-28898Shared CWE-116
CVE-2025-8405Shared CWE-116
CVE-2026-25940Shared CWE-116
CVE-2024-34739Shared CWE-116
CVE-2023-26472Shared CWE-116

Affected Assets

mongodb
c\+\+ driver
3.0.0 — 4.5.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.2.1
  • V1.2.3

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-116

Validating that output matches expected content directly mitigates failures to properly encode or escape data for its destination context.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
prevents

Secure SDLC practices directly require proper output encoding to prevent injection and message malformation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure development life cycle mandates output encoding/escaping practices that directly prevent improper encoding.

prevents

Application security requirements include explicit rules for safe output handling and encoding.

prevents

Secure architecture principles reduce the likelihood of missing encoding but do not prescribe the actual technique.

prevents

Secure coding standards explicitly require correct output encoding and escaping to preserve message structure.

finds

Security testing can detect missing or incorrect encoding but does not itself implement the control.

References