# CVE-2026-75894: Osmocom osmo-iuh assertion failure in RANAP NAS-PDU handling

Source: https://junglewise.ai/threats/cve-2026-75894-in-osmo-iuh-from-0-1-0-through-1-8-0-a-reachable-assertion-was  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-18. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-75894 · Severity: high · CVSS 7.5 · Published 2026-09-18

osmo-iuh is a library that implements the Iuh interface protocol used in cellular networks for femtocell connectivity. A remote attacker connected as a femtocell peer can crash the gateway software by sending a specially crafted message with an oversized payload, causing a denial of service and potential outage of femtocell services.

Vendors: [Osmocom](https://junglewise.ai/threats/vendors/osmocom).

## Quick answers

**Is CVE-2026-75894 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-75894 being exploited in the wild.

**How severe is CVE-2026-75894?** High severity, with a CVSS score of 7.5, published 18 September 2026.

**Which products and versions are affected?** Osmocom Osmo-Iuh 0.1.0 through 1.8.0.

**Is there a fix for CVE-2026-75894?** 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-2026-75894 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-75894?** Check whether you run Osmocom Osmo-Iuh 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 ranap_handle_co_dt() and ranap_handle_co_initial_ue() functions in osmo-iuh copy attacker-controlled NAS-PDU data into a fixed 256-byte message buffer without validating the input size. When a NAS-PDU larger than 256 bytes is received, the msgb_put() call triggers an assertion that crashes the process. An unauthenticated network peer (femtocell) can exploit this to remotely crash osmo-hnbgw or osmo-hnodeb.

## Affected products

- Osmocom osmo-iuh 0.1.0 through 1.8.0

## Timeline

- 2026-09-18: disclosed

## References

- [https://cgit.osmocom.org/osmo-iuh/commit/?id=f06967126f486bcb185ccf3d1a8f9bc02c4da1f6](https://cgit.osmocom.org/osmo-iuh/commit/?id=f06967126f486bcb185ccf3d1a8f9bc02c4da1f6)