Summary
Out-of-Bounds Slice Access in free5GC CHF Leading to DoS
Workarounds
- Restrict access to the
nchf-convergedchargingrecharge 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.
- Ensure panic recovery, monitoring, and alerting are enabled.
Impact
This is 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.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-32937? CVE-2026-32937 is a high-severity security vulnerability in github.com/free5gc/chf (go), affecting versions < 1.2.2. It is fixed in 1.2.2.
- Which versions of github.com/free5gc/chf are affected by CVE-2026-32937? github.com/free5gc/chf (go) versions < 1.2.2 is affected.
- Is there a fix for CVE-2026-32937? Yes. CVE-2026-32937 is fixed in 1.2.2. Upgrade to this version or later.
- Is CVE-2026-32937 exploitable, and should I be worried? Whether CVE-2026-32937 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-32937 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-32937? Upgrade
github.com/free5gc/chfto 1.2.2 or later.