CVE-2026-32937 free5GC CHF has Out-of-Bounds Slice Access that Leads to DoS
Authenticated attackers can trigger server panics in free5GC CHF via out-of-bounds slice access, causing service disruption and log flooding.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-32937?
CVE-2026-32937 is a high-severity denial of service vulnerability in Free5gc Free5gc, published on 20 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-129
Which versions are affected by CVE-2026-32937?
3 open source packages ship an affected version, including github.com/free5gc/chf. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/free5gc/chf Go | All versions | 1.2.2 |
github.com/free5gc/chf Go | All versions | 1.2.2 |
github.com/free5gc/chf Go | All versions | 1.2.2 |
Products include Free5gc Free5gc.
How do I fix CVE-2026-32937?
Upgrade github.com/free5gc/chf to 1.2.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-32937 being exploited?
There is no known exploitation of CVE-2026-32937 in the wild and no public exploit code.
Other vulnerabilities in Free5gc Free5gc
- CVE-2026-44327 free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler
- CVE-2026-44329 free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers
- CVE-2026-44330 free5GC's NEF nnef-pfdmanagement API is unauthenticated; forged bearer tokens can read PFD data and create/delete PFD subscriptions
- CVE-2025-63679 Memory corruption in n/a
- CVE-2026-44315 free5GC's NEF 3gpp-pfd-management API is unauthenticated; forged bearer tokens can create, read, and delete PFD transactions
Sources
Also known as GHSA-6g43-577r-wf4x, GO-2026-4750.