Vulnerability Description
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.10.0, the STUN/TURN attribute parsing functions in coturn perform unsafe pointer casts from uint8_t * to uint16_t * without alignment checks. When processing a crafted STUN message with odd-aligned attribute boundaries, this results in misaligned memory reads at ns_turn_msg.c. On ARM64 architectures (AArch64) with strict alignment enforcement, this causes a SIGBUS signal that immediately kills the turnserver process. An unauthenticated remote attacker can crash any ARM64 coturn deployment by sending a single crafted UDP packet. This vulnerability is fixed in 4.10.0.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Coturn Project | Coturn | < 4.10.0 |
Related Weaknesses (CWE)
References
- https://github.com/coturn/coturn/security/advisories/GHSA-j662-9wcj-mf36ExploitVendor Advisory
- https://github.com/coturn/coturn/security/advisories/GHSA-j662-9wcj-mf36ExploitVendor Advisory
FAQ
What is CVE-2026-40613?
CVE-2026-40613 is a vulnerability with a CVSS score of 7.5 (HIGH). Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.10.0, the STUN/TURN attribute parsing functions in coturn perform unsafe pointer casts from uint8_t * to uint16_t * with...
How severe is CVE-2026-40613?
CVE-2026-40613 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40613?
Check the references section above for vendor advisories and patch information. Affected products include: Coturn Project Coturn.