# CVE-2026-75438: Open5GS buffer overflow in time parsing

Source: https://junglewise.ai/threats/cve-2026-75438-open5gs-buffer-overflow-in-time-parsing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-04. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-75438 · Severity: high · CVSS 7.5 · Published 2026-09-04

Open5GS is a 5G core network implementation that processes telecommunications signaling and subscriber data. A buffer overflow in the time parsing function allows remote attackers to crash the service, disrupting network operations and causing denial of service for all users connected to the affected core.

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

## Quick answers

**Is CVE-2026-75438 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-75438 being exploited in the wild.

**How severe is CVE-2026-75438?** High severity, with a CVSS score of 7.5, published 4 September 2026.

**Which products and versions are affected?** Open5GS 2.7.7.

**Is there a fix for CVE-2026-75438?** 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-2026-75438 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-75438?** 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 buffer overflow vulnerability exists in the ogs_sbi_time_parse() function in Open5GS v2.7.7. The vulnerability is triggered via the SBI (Service Based Interface) protocol when processing malformed time values, specifically UE location timestamp fields. An unauthenticated remote attacker on the network can send crafted input to overflow a buffer, leading to process crash and denial of service. No remote code execution or authentication bypass is reported. Patch availability is not mentioned in the advisory.

## Affected products

- Open5GS Open5GS 2.7.7

## Timeline

- 2026-09-04: disclosed
- 2026-09-02: other: exploit proof-of-concept published on GitHub

## References

- [https://gist.github.com/hackeryounow/c299d593b89fd6487cab4182c8aecabf](https://gist.github.com/hackeryounow/c299d593b89fd6487cab4182c8aecabf)
- [https://github.com/hackeryounow/5GCVulDB/blob/main/smf_crash_uelocationtimestamp.sh](https://github.com/hackeryounow/5GCVulDB/blob/main/smf_crash_uelocationtimestamp.sh)

## 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)