CVE-2026-40613

high

Coturn is a free open source implementation of TURN and STUN Server.

Vendor / product: Coturn Project — coturn

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

7.5

7.5 (CVSS v3.1)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity source: NVD CVSS v3.1 (security-advisories@github.com)

Timeline (UTC)

Published: 2026-04-21 19:16

Modified: 2026-11-11 23:10

NVD status: Analyzed

Last synced 3 hours ago

Verified against the source API 2026-11-11 23:12 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

coturn_project / coturn <4.10.0

Weakness classification (CWE)

CWE-704

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/coturn/coturn/security/advisories/GHSA-j662-9wcj-mf36

References

https://github.com/coturn/coturn/security/advisories/GHSA-j662-9wcj-mf36 security-advisories@github.com
https://github.com/coturn/coturn/security/advisories/GHSA-j662-9wcj-mf36 134c704f-9b21-4f2e-91b3-4a467353bcc0

Data sources

NVD CVE API 2.0 — fetched 2026-11-11 23:12 UTC · record ↗

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