# CVE-2026-7183: aligungr UERANSIM uncaught exception in Radio Link Simulation Layer

Source: https://junglewise.ai/threats/cve-2026-7183-aligungr-ueransim-uncaught-exception-in-radio-link-simulation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-27. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-7183 · Severity: medium · CVSS 5.3 · Published 2026-04-27

UERANSIM is an open-source simulator for 5G mobile phones and base stations used for testing 5G core networks. A vulnerability in its radio link simulation layer allows a remote attacker to crash the software by sending specially crafted messages. This results in a denial-of-service condition, disrupting 5G network testing and simulation activities.

Technologies: [Aligungr UERANSIM](https://junglewise.ai/threats/technologies/ueransim). Vendors: [Aligungr](https://junglewise.ai/threats/vendors/aligungr).

## Quick answers

**Is CVE-2026-7183 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-7183 being exploited in the wild.

**How severe is CVE-2026-7183?** Medium severity, with a CVSS score of 5.3, published 27 April 2026.

**Which products and versions are affected?** Aligungr UERANSIM up to 3.2.7.

**Is there a fix for CVE-2026-7183?** A patch was published on 2026-04-15: Patch ca1a66fffe282767bb08618af9f848e3b68ea47b released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-7183 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-7183?** Check whether you run Aligungr UERANSIM 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 vulnerability exists in the Radio Link Simulation Layer of UERANSIM up to version 3.2.7. The root cause is located in the rls::DecodeRlsMessage function within src/lib/rls/rls_pdu.cpp, where improper manipulation of the pduLength argument leads to an uncaught exception (CWE-248). A remote, unauthenticated attacker can exploit this over the network to cause the application to terminate unexpectedly. The issue has been addressed in version 3.2.8 through security hardening of the RLS layer.

## Affected products

- aligungr UERANSIM up to 3.2.7

## Timeline

- 2026-04-15: patched: Patch ca1a66fffe282767bb08618af9f848e3b68ea47b released
- 2026-04-27: disclosed: Initial disclosure via VulDB/NVD

## References

- [https://github.com/aligungr/UERANSIM/](https://github.com/aligungr/UERANSIM/)
- [https://github.com/aligungr/UERANSIM/commit/ca1a66fffe282767bb08618af9f848e3b68ea47b](https://github.com/aligungr/UERANSIM/commit/ca1a66fffe282767bb08618af9f848e3b68ea47b)
- [https://github.com/aligungr/UERANSIM/releases/tag/v3.2.8](https://github.com/aligungr/UERANSIM/releases/tag/v3.2.8)
- [https://vuldb.com/submit/800026](https://vuldb.com/submit/800026)
- [https://vuldb.com/vuln/359784](https://vuldb.com/vuln/359784)
- [https://vuldb.com/vuln/359784/cti](https://vuldb.com/vuln/359784/cti)

## Related threats

- [aligungr UERANSIM exception in NAS message parsing](https://junglewise.ai/threats/cve-2026-101035-a-flaw-has-been-found-in-aligungr-ueransim-up-to-3-3-0-this)
- [UERANSIM null pointer dereference in ULInformationTransfer handler](https://junglewise.ai/threats/cve-2026-100892-a-vulnerability-was-found-in-aligungr-ueransim-up-to-3-3-0-this)