PT-2026-34043 · Coturn · Coturn

Published 2026-04-21 · Updated 2026-04-22 · CVE-2026-40613

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Coturn versions prior to 4.10.0

Description STUN/TURN attribute parsing functions perform unsafe pointer casts from uint8 t * to uint16 t * without alignment checks. When processing a crafted STUN message with odd-aligned attribute boundaries, misaligned memory reads occur at ns turn msg.c. On ARM64 architectures (AArch64) with strict alignment enforcement, this triggers a SIGBUS signal, which is a signal sent to a process when it does not have permission to access a memory location or the memory is physically unavailable, resulting in the immediate termination of the turnserver process. An unauthenticated remote attacker can cause a crash by sending a single crafted UDP packet.

Recommendations Update to version 4.10.0.

Exploit

Fix

DoS

Incorrect Type Conversion or Cast

Weakness Enumeration

CWE-704

Related Identifiers

CVE-2026-40613

Affected Products

Coturn

References · 10

• 🔥 https://github.com/coturn/coturn/security/advisories/GHSA-j662-9wcj-mf36 · Exploit
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-40613 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-40613 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-40613 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-40613 · Security Note
• https://ubuntu.com/security/CVE-2026-40613 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-40613 · Vendor Advisory
• https://twitter.com/VulmonFeeds/status/2046774126522552364 · Twitter Post
• https://twitter.com/CVEnew/status/2046675001185603773 · Twitter Post
• https://twitter.com/cypherbyteio/status/2046910637435990516 · Twitter Post