# CVE-2026-116543: Open5GS heap out-of-bounds write in multipart parsing

Source: https://junglewise.ai/threats/cve-2026-116543-open5gs-1-3-0-through-2-8-0-contains-a-heap-out-of-bounds-write  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-116543 · Severity: high · CVSS 7.5 · Published 2026-10-26

Open5GS is the core network software for 5G and LTE mobile networks. An unauthenticated attacker can crash a network function by sending a specially crafted multipart request with an empty boundary, corrupting memory and causing the service to stop responding. This disruption affects the availability of 5G/LTE network services.

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

## Quick answers

**Is CVE-2026-116543 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-116543 being exploited in the wild.

**How severe is CVE-2026-116543?** High severity, with a CVSS score of 7.5, published 26 October 2026.

**Which products and versions are affected?** Open5GS 1.3.0 through 2.8.0.

**Is there a fix for CVE-2026-116543?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-116543 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-116543?** 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

A heap out-of-bounds write vulnerability exists in the parse_multipart() function when processing multipart/related requests with an empty boundary string. The vulnerable lookbehind buffer logic fails to handle this edge case, allowing an unauthenticated attacker to overflow heap memory. The vulnerability affects the SBI (Service-Based Interface) and can be triggered with a single crafted HTTP request, resulting in denial of service.

## Affected products

- Open5GS Open5GS 1.3.0 through 2.8.0

## Timeline

- 2026-10-26: disclosed

## References

- [https://github.com/open5gs/open5gs](https://github.com/open5gs/open5gs)
- [https://github.com/open5gs/open5gs/blob/v2.8.0/lib/sbi/contrib/multipart_parser.c](https://github.com/open5gs/open5gs/blob/v2.8.0/lib/sbi/contrib/multipart_parser.c)

## 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 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)
- [Open5GS heap out-of-bounds read in PFCP parsing](https://junglewise.ai/threats/cve-2026-108102-open5gs-through-2-8-0-contains-a-heap-out-of-bounds-read)