# CVE-2026-37221: EURECOM FlexRIC denial of service via forged subscription response

Source: https://junglewise.ai/threats/cve-2026-37221-eurecom-flexric-denial-of-service-via-forged-subscription  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-01. Updated: 2026-06-01  
License: CC BY 4.0 with a link back

CVE-2026-37221 · Severity: info · CVSS 7.5 · Published 2026-06-01

FlexRIC is a software controller used in Open RAN (Radio Access Network) environments to manage cellular network functions. A vulnerability allows an unauthenticated remote attacker to crash the controller by sending a specially crafted message. This results in a denial-of-service (DoS) condition, potentially disrupting mobile network operations and management.

Technologies: [EURECOM FlexRIC](https://junglewise.ai/threats/technologies/flexric). Vendors: [EURECOM](https://junglewise.ai/threats/vendors/eurecom).

## Quick answers

**Is CVE-2026-37221 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-37221 being exploited in the wild.

**How severe is CVE-2026-37221?** Informational severity, with a CVSS score of 7.5, published 1 June 2026.

**Which products and versions are affected?** EURECOM FlexRIC v2.0.0 through commit 6a595d8b.

**Is there a fix for CVE-2026-37221?** 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-2026-37221 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-37221?** Check whether you run EURECOM FlexRIC 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 Reachable Assertion (CWE-617) exists in the near-RT RIC component of FlexRIC v2.0.0. The vulnerability is located in the 'stop_pending_event()' function within 'src/ric/msg_handler_ric.c'. When the RIC receives a 'RIC_SUBSCRIPTION_RESPONSE' with an unknown 'ric_id', it attempts to extract a non-existent key from a bimap without prior validation. In debug builds, this triggers an 'assert()' leading to a SIGABRT; in release builds where assertions are stripped, it results in a NULL pointer dereference and a SIGSEGV. Attackers can exploit this by sending a forged SCTP packet to port 36421.

## Affected products

- EURECOM FlexRIC v2.0.0 through commit 6a595d8b

## Timeline

- 2026-06-01: disclosed
- 2026-06-01: advisory

## References

- [https://github.com/MinamiKotor1/oran-security-advisories-zhongnan-luo/blob/main/advisories/CVE-2026-37221.md](https://github.com/MinamiKotor1/oran-security-advisories-zhongnan-luo/blob/main/advisories/CVE-2026-37221.md)
- [https://gitlab.eurecom.fr/mosaic5g/flexric](https://gitlab.eurecom.fr/mosaic5g/flexric)

## Related threats

- [EURECOM FlexRIC resource leak via multiple xApp identity bindings](https://junglewise.ai/threats/cve-2026-37234-eurecom-flexric-resource-leak-via-multiple-xapp-identity-bindings)
- [EURECOM FlexRIC xApp impersonation and DoS in iApp component](https://junglewise.ai/threats/cve-2026-37235-eurecom-flexric-xapp-impersonation-and-dos-in-iapp-component)
- [EURECOM FlexRIC authorization bypass in iApp xApp isolation](https://junglewise.ai/threats/cve-2026-37233-eurecom-flexric-authorization-bypass-in-iapp-xapp-isolation)
- [EURECOM FlexRIC denial of service via xapp_id integer wraparound](https://junglewise.ai/threats/cve-2026-37231-eurecom-flexric-denial-of-service-via-xapp-id-integer-wraparound)
- [EURECOM FlexRIC NULL pointer dereference in near-RT RIC](https://junglewise.ai/threats/cve-2026-37230-eurecom-flexric-null-pointer-dereference-in-near-rt-ric)