# CVE-2026-78157: Open5GS Rx AA-Request Handler out-of-bounds read

Source: https://junglewise.ai/threats/cve-2026-78157-open5gs-rx-aa-request-handler-out-of-bounds-read  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-24. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-78157 · Severity: high · CVSS 7.4 · Published 2026-08-24

Open5GS is an open-source implementation of 5G core network infrastructure used by telecom operators. A vulnerability in the Rx AA-Request handler component allows remote attackers to craft malformed messages containing improperly formatted AVP fields, triggering an out-of-bounds memory read that could lead to service disruption or information disclosure.

Technologies: [Open5GS](https://junglewise.ai/threats/technologies/open5gs). Vendors: [Open5GS](https://junglewise.ai/threats/vendors/open5gs).

## Quick answers

**Is CVE-2026-78157 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-78157 being exploited in the wild.

**How severe is CVE-2026-78157?** High severity, with a CVSS score of 7.4, published 24 August 2026.

**Which products and versions are affected?** Open5GS 2.8.0.

**Is there a fix for CVE-2026-78157?** A patch was published: Patch available as commit c18dc6938bf63cc7374315d3dca303d92066e746 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-78157 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-78157?** Check whether you run Open5GS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in the pcrf_rx_aar_cb function in src/pcrf/pcrf-rx-path.c where Framed-IP-Address and Framed-IPv6-Prefix AVP fields are processed without proper length validation. An attacker can send a specially crafted AA-Request (Rx protocol) with a malformed Framed-IP-Address shorter than 4 bytes or a Framed-IPv6-Prefix shorter than expected, causing an out-of-bounds read when the code attempts to use these fields as hash keys or dereference them. The attack requires network-level access to the PCRF component and is remotely exploitable. A patch (commit c18dc6938bf63cc7374315d3dca303d92066e746) adds validation to check AVP lengths before use.

## Affected products

- Open5GS Open5GS 2.8.0

## Timeline

- 2026-08-24: disclosed
- patched: Patch available as commit c18dc6938bf63cc7374315d3dca303d92066e746

## References

- [https://github.com/open5gs/open5gs/](https://github.com/open5gs/open5gs/)
- [https://github.com/open5gs/open5gs/commit/c18dc6938bf63cc7374315d3dca303d92066e746](https://github.com/open5gs/open5gs/commit/c18dc6938bf63cc7374315d3dca303d92066e746)

## Related threats

- [Open5GS HTTP/2 SBI server memory exhaustion](https://junglewise.ai/threats/cve-2026-106806-a-memory-exhaustion-issue-exists-in-open5gs-v2-8-0-in-the-http-2)
- [open5GS PFCP transaction handling denial of service](https://junglewise.ai/threats/cve-2026-106807-a-denial-of-service-vulnerability-exists-in-open5gs-v2-8-0-in)
- [Open5GS heap out-of-bounds write in multipart parsing](https://junglewise.ai/threats/cve-2026-116543-open5gs-1-3-0-through-2-8-0-contains-a-heap-out-of-bounds-write)
- [Open5GS assertion failure in SGSN context request handling](https://junglewise.ai/threats/cve-2026-108105-open5gs-through-2-8-0-contains-a-reachable-assertion)
- [Open5GS heap out-of-bounds read in PFCP parsing](https://junglewise.ai/threats/cve-2026-108103-open5gs-through-2-8-0-contains-a-heap-out-of-bounds-read)