CVE-2026-32937: free5GC is an open source 5G core network. free5GC CHF prior to version 1.2.2 has an out-of-bounds slice access vulnerability in the CHF `nchf-converg...

Description

free5GC is an open source 5G core network. free5GC CHF prior to version 1.2.2 has an out-of-bounds slice access vulnerability in the CHF `nchf-convergedcharging` service. A valid authenticated request to PUT `/nchf-convergedcharging/v3/recharging/:ueId?ratingGroup=...` can trigger a server-side panic in `github.com/free5gc/chf/internal/sbi.(*Server).RechargePut(...)` due to an out-of-range slice access. In the reported runtime, Gin recovery converts the panic into HTTP 500, but the recharge path remains remotely panic-triggerable and can be abused repeatedly to degrade recharge functionality and flood logs. In deployments without equivalent recovery handling, this panic may cause more severe service disruption. free5GC CHF patches the issue. Some workarounds are available: Restrict access to the `nchf-convergedcharging` recharge endpoint to strictly trusted NF callers only; apply rate limiting or network ACLs in front of the CHF SBI interface to reduce repeated panic-trigger attempts; if the recharge API is not required, temporarily disable or block external reachability to this route; and/or ensure panic recovery, monitoring, and alerting are enabled.

Metrics

CVSS 3.1

6.5/10

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

CVSS 4.0

7.1/10

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

0.40%

32.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-129

Affected Software

Vendor	Product	Versions
Free5gc	Free5gc	< 1.2.2

References

https://github.com/free5gc/chf/commit/55af766f321a00afa978e806548c96f8a7d2433ePatch
https://github.com/free5gc/chf/pull/61Issue Tracking
https://github.com/free5gc/free5gc/issues/864Issue Tracking
https://github.com/free5gc/free5gc/security/advisories/GHSA-6g43-577r-wf4xVendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2026-32937?

free5GC is an open source 5G core network. free5GC CHF prior to version 1.2.2 has an out-of-bounds slice access vulnerability in the CHF `nchf-convergedcharging` service. A valid authenticated request to PUT `/nchf-convergedcharging/v3/recharging/:ueId?ratingGroup=...` can trigger a server-side panic in `github.com/free5gc/chf/internal/sbi.(*Server).RechargePut(...)` due to an out-of-range slice access. In the reported runtime, Gin recovery converts the panic into HTTP 500, but the recharge path remains remotely panic-triggerable and can be abused repeatedly to degrade recharge functionality and flood logs. In deployments without equivalent recovery handling, this panic may cause more severe service disruption. free5GC CHF patches the issue. Some workarounds are available: Restrict access to the `nchf-convergedcharging` recharge endpoint to strictly trusted NF callers only; apply rate limiting or network ACLs in front of the CHF SBI interface to reduce repeated panic-trigger attempts; if the recharge API is not required, temporarily disable or block external reachability to this route; and/or ensure panic recovery, monitoring, and alerting are enabled.

How severe is CVE-2026-32937?

CVE-2026-32937 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2026-32937?

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.