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CVE-2026-40613highCWE-704

Coturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64)

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.5epss 1.1%
exploitation probability
1.1%top 37% of all CVEs
observed exploitation
nono source reports it
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
coturn · coturn