Quick answers
- Is CVE-2026-15720 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-15720 being exploited in the wild.
- How severe is CVE-2026-15720?
- High severity, with a CVSS score of 8.6, published 14 July 2026.
- Which products and versions are affected?
- Open5GS <= 2.7.7.
- Is there a fix for CVE-2026-15720?
- 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-2026-15720 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-15720?
- 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 read exists in the `ogs_nas_5gs_decode_5gs_mobile_identity()` function within `lib/nas/5gs/ies.c`. The root cause is a failure to validate that the attacker-declared length of a mobile identity (GUTI or 5G-S-TMSI) is sufficient for the identity type specified. When the AMF processes a NAS Registration, Deregistration, or Service Request, it aliases a pointer into the packet buffer without a minimum-length check and subsequently casts it to a fixed-size struct. An attacker using a rogue base station (gNB) can send a malformed NAS message before authentication occurs, causing the AMF to read past the buffer boundary. In hardened or ASAN-enabled builds, this results in an immediate crash of the AMF process, dropping all active subscriber sessions.
Affected products
- Open5GS Open5GS <= 2.7.7
Timeline
- 2026-06-05: advisory: Vendor advisory published on GitHub
- 2026-07-14: disclosed: CVE published to NVD