CVE-2026-40613: high-severity vulnerability in coturn
Coturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64)
Published
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 1.5%
exploitation probability
1.5%top 26% 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 · coturnRelated CVEs — coturn
In the same product, most dangerous first.
CVE-2020-4067HIGHImproper Initialization in coturnEPSS 1.9%CVE-2020-26262HIGHLoopback bypass in CoturnEPSS 1.5%CVE-2026-53448HIGHCoturn: SQL Injection in HTTPS Admin Panel Delete OperationsEPSS 0.7%CVE-2026-43994HIGHCoturn: Stack buffer overflow in decode_oauth_token_gcm()EPSS 0.7%CVE-2026-73214HIGHcoturn allocates a full per-peer SSL/session before verifying the DTLS cookie, enabling source-spoofing/botnet state-exhaustion DoSEPSS 0.6%CVE-2026-73216MEDIUMcoturn: mobility disconnects bypass allocation quotas and exhaust relay capacityEPSS 0.6%