CVE-2026-27643

Info Disclosure in Free5Gc Udr ≤ 1.4.1

Public PoCInfo Disclosure

Published

24 February 2026

Modified

25 February 2026

Patch / advisory

View advisory

CVSS Score v4 6.6

Click a component to see what it means

Raw vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/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 0.0027 20th percentile

Risk Priority 39 floored blend · peak EPSS

Summary

CVE-2026-27643 is a medium-severity Generation of Error Message Containing Sensitive Information (CWE-209) vulnerability in Free5Gc Udr. Its CVSS base score is 6.6 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Software (T1592.002); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-11 (Error Handling) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-7462

Vulnerability Data

free5GC UDR is the user data repository (UDR) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, the NEF component reliably leaks internal parsing error details (e.g., invalid character…

'n' after top-level value) to remote clients, which can aid attackers in service fingerprinting. All deployments of free5GC using the Nnef_PfdManagement service may be affected. free5gc/udr pull request 56 contains a patch for the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch.

CWE(s): CWE-209

Related Threats

MITRE ATT&CK Enterprise Techniques

T1592.002 Software Reconnaissance

Adversaries may gather information about the victim's host software that can be used during targeting.

attack.mitre.org →

T1082 System Information Discovery Discovery

An adversary may attempt to get detailed information about the operating system and hardware, including version, patches, hotfixes, service packs, and architecture.

attack.mitre.org →

T1592 Gather Victim Host Information Reconnaissance

Adversaries may gather information about the victim's hosts that can be used during targeting.

attack.mitre.org →

T1595 Active Scanning Reconnaissance

Adversaries may execute active reconnaissance scans to gather information that can be used during targeting.

attack.mitre.org →

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

CVEs Like This One

CVE-2025-69253Same product: Free5Gc Udr

CVE-2025-69208Same product: Free5Gc Udr

CVE-2026-33192Same vendor: Free5Gc

CVE-2026-33065Same vendor: Free5Gc

CVE-2026-40343Same product: Free5Gc Udr

CVE-2026-42459Same vendor: Free5Gc

CVE-2023-34339Shared CWE-209

CVE-2025-0279Shared CWE-209

CVE-2025-12365Shared CWE-209

CVE-2024-52043Shared CWE-209

Affected Assets

free5gc

udr

≤ 1.4.1

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)

V16.5.1

Mitigating Controls (NIST 800-53 r5) AI

SI-11 Error Handling good match

si-11 directly requires error messages to avoid revealing exploitable information about the system or its data.

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 mostly match

prevents

Secure SDLC practices directly require sanitized error handling to prevent sensitive data disclosure.

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.8.28 Secure coding mostly match

prevents

Secure coding standards explicitly forbid exposing sensitive data in errors.

A.8.29 Security testing in development and acceptance mostly match

finds

Security testing can detect error messages that leak sensitive information.

A.8.15 Logging partial match

degrades

Logging policy can require suppression of sensitive data in error messages.

A.8.25 Secure development life cycle partial match

prevents

Secure SDLC mandates error-handling rules that avoid leaking sensitive information.