CVE-2026-96748

Published

24 September 2026

Modified

24 September 2026

CVSS Score v4 8.3

Click a component to see what it means

Raw vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/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 0.0026 16th percentile

Risk Priority 42 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-2026-96748 is a high-severity Hex Encoding (CWE-177) vulnerability. Its CVSS base score is 8.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 16th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-86347

Vulnerability Data

PyMongo's connection string parsing decodes percent-encoded characters in the host portion before the host list is separated on its delimiters. When an application places a hostname value supplied by an unauthenticated party into a connection string, that party may cause…

additional servers of their choosing to be added to the application's database client. The application may then send its authentication exchange and database operations to one of those servers, which can observe limited information and return altered results.

CWE(s): CWE-177

Related Threats

MITRE ATT&CK Enterprise Techniques

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.

attack.mitre.org →

Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-15371Shared CWE-177

CVE-2026-59083Shared CWE-177

CVE-2026-29045Shared CWE-177

CVE-2026-41041Shared CWE-177

CVE-2026-22031Shared CWE-177

CVE-2026-76172Shared CWE-177

CVE-2024-48866Shared CWE-177

CVE-2026-6414Shared CWE-177

CVE-2025-11990Shared CWE-177

CVE-2026-22037Shared CWE-177

Affected Assets

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)

V1.2.2

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation partial match

Proper input validation requires decoding and checking URL-encoded data before use, directly stopping the weakness from being exploitable.

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 correct URL-encoding/decoding and input validation during development.

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.

A.5.14 Information transfer partial match

removes

A.8.1 User end point devices partial match

removes

A.8.19 Installation of software on operational systems partial match

removes

A.8.25 Secure development life cycle partial match

prevents

Secure SDLC processes include validation steps that reduce CWE-177, yet the control is broader than this single weakness.

A.8.26 Application security requirements partial match

prevents

Application security requirements explicitly call for input validation and canonicalization, directly preventing improper URL decoding.