CVE-2026-40613
Coturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64)
- State
- Published
- Severity
- 7.5 High
- Published
- Apr 21, 2026
- Updated
- Apr 21, 2026
- Reserved
- Apr 14, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
Weaknesses
- CWE-704 Incorrect Type Conversion or Cast
Affected Products
| Product | Versions |
|---|---|
coturncoturn |
|
References
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