Vulnerability · Published Apr 21, 2026 · Assigned by GitHub_M

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

Medium 5.5

In plain English

A medium-severity security flaw in amf from free5gc. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).

Severity (CVSS 4.0)5.5Medium

Exploit odds (30 days)0.3%top 79.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/free5gc/amf	no fix listed	GHSA-r99v-75p9-xqm5
Go	github.com/free5gc/amf	no fix listed	GO-2026-5613

Affected products (as reported)

Vendor	Product	Versions
free5gc	amf	< 1.4.3

Weakness: CWE-440 · 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

References

https://github.com/free5gc/free5gc/security/advisories/GHSA-r99v-75p9-xqm5 x_refsource_CONFIRM
https://github.com/free5gc/amf/releases/tag/v1.4.3 x_refsource_MISC