CVE-2026-33062: free5GC is an open source 5G core network. free5GC NRF prior to version 1.4.2 has an Improper Input Validation vulnerability leading to Denial of Serv...

Description

free5GC is an open source 5G core network. free5GC NRF prior to version 1.4.2 has an Improper Input Validation vulnerability leading to Denial of Service. All deployments of free5GC using the NRF discovery service are affected. The `EncodeGroupId` function attempts to access array indices [0], [1], [2] without validating the length of the split data. When the parameter contains insufficient separator characters, the code panics with "index out of range". A remote attacker can cause the NRF service to panic and crash by sending a crafted HTTP GET request with a malformed `group-id-list` parameter. This results in complete denial of service for the NRF discovery service. free5GC NRF version 1.4.2 fixes the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch or restrict access to the NRF API to trusted sources only.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS 4.0

8.7/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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

EPSS Probability

0.67%

47.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-284

Affected Software

Vendor	Product	Versions
Free5gc	Free5gc	< 1.4.2

References

https://github.com/free5gc/free5gc/issues/777Exploit, Issue Tracking
https://github.com/free5gc/free5gc/security/advisories/GHSA-7c47-xr7q-p6hgVendor Advisory
https://github.com/free5gc/nrf/commit/dac77d8f8f2e0f041c5634fb3c685dcb9734b872Patch
https://github.com/free5gc/nrf/pull/80Patch

Timeline

Published: Mar 20, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-33062?

free5GC is an open source 5G core network. free5GC NRF prior to version 1.4.2 has an Improper Input Validation vulnerability leading to Denial of Service. All deployments of free5GC using the NRF discovery service are affected. The `EncodeGroupId` function attempts to access array indices [0], [1], [2] without validating the length of the split data. When the parameter contains insufficient separator characters, the code panics with "index out of range". A remote attacker can cause the NRF service to panic and crash by sending a crafted HTTP GET request with a malformed `group-id-list` parameter. This results in complete denial of service for the NRF discovery service. free5GC NRF version 1.4.2 fixes the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch or restrict access to the NRF API to trusted sources only.

How severe is CVE-2026-33062?

CVE-2026-33062 has a CVSS score of 8.7/10 (HIGH severity). The EPSS model estimates a 0.67% probability of exploitation in the next 30 days.

How do I fix CVE-2026-33062?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.