CVE-2026-40613
Coturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64)
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
Coturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64)
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.
- Record
CVE-2026-40613- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-704
- Updated
- 2026-11-02
EUVDEUVD-2026-24228
7.5
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.
- Record
EUVD-2026-24228- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2026-40613- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-704
- Updated
- 2026-11-02
OSVALPINE-CVE-2026-40613
7.5
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.
- Record
ALPINE-CVE-2026-40613- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
OSV
7.5
Coturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64)
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.
- Record
CVE-2026-40613- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-704
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-40613
7.5
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.
- Record
DEBIAN-CVE-2026-40613- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-40613
7.5
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.
- Record
UBUNTU-CVE-2026-40613- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVMGASA-2026-0217 No score
Updated coturn packages fix security vulnerabilities
CVE-2026-40613 Coturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64)
- Record
MGASA-2026-0217- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11617-1 No score
coturn-4.17.2-1.1 on GA media
These are all security issues fixed in the coturn-4.17.2-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11617-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
coturnAlpine:v3.23 |
before 4.10.0-r0 | 4.10.0-r0 |
coturnAlpine:v3.24 |
before 4.10.0-r0 | 4.10.0-r0 |
coturnDebian:12 |
All versions, plus listed versions 4.12.0-14.14.0-14.15.0-14.18.0-14.6.1-14.6.1-2 |
None known |
coturnDebian:13 |
All versions, plus listed versions 4.12.0-14.14.0-14.15.0-14.18.0-14.6.1-2 |
None known |
coturnDebian:14 |
before 4.12.0-1, plus listed versions 4.6.1-2 |
4.12.0-1 |
coturnMageia:9 |
before 4.6.2-1.2.mga9 | 4.6.2-1.2.mga9 |
coturnUbuntu:16.04:LTS |
All versions, plus listed versions 4.4.5.4-24.5.0.2-34.5.0.3-14.5.0.3-1build14.5.0.3-1ubuntu0.24.5.0.3-1ubuntu0.34.5.0.3-1ubuntu0.4 |
None known |
coturnUbuntu:18.04:LTS |
All versions, plus listed versions 4.5.0.6-1ubuntu24.5.0.7-1ubuntu14.5.0.7-1ubuntu24.5.0.7-1ubuntu2.18.04.14.5.0.7-1ubuntu2.18.04.24.5.0.7-1ubuntu2.18.04.3 |
None known |
coturnUbuntu:20.04:LTS |
All versions, plus listed versions 4.5.1.1-1.1build14.5.1.1-1.1build24.5.1.1-1.1ubuntu0.20.04.14.5.1.1-1.1ubuntu0.20.04.2 |
None known |
coturnUbuntu:22.04:LTS |
All versions, plus listed versions 4.5.2-34.5.2-3.1~ubuntu22.04.1 |
None known |
Show 5 moreShow less
| Package | Affected | Fixed |
|---|---|---|
coturnUbuntu:24.04:LTS |
All versions, plus listed versions 4.6.1-1build14.6.1-1build24.6.1-1build34.6.1-1build4 |
None known |
coturnUbuntu:25.10 |
All versions, plus listed versions 4.6.1-2build1 |
None known |
coturnUbuntu:26.10 |
All versions, plus listed versions 4.6.1-2build24.12.0-14.14.0-14.15.0-14.18.0-1 |
None known |
coturnUbuntu:26.04:LTS |
All versions, plus listed versions 4.6.1-2build14.6.1-2build2 |
None known |
coturnopenSUSE:Tumbleweed From an advisory covering 17 CVEs |
before 4.17.2-1.1 | 4.17.2-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected, aliases, references | OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-40613 is a high vulnerability (CVSS 7.5) in Coturn, published April 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.12%, the 66th percentile. Fixed in coturn 4.10.0-r0.
References
github.com/coturn/coturn/security/advisories/GHSA-j662-9wcj-mf36
security.alpinelinux.org/vuln/CVE-2026-40613
github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40613.json
nvd.nist.gov/vuln/detail/CVE-2026-40613
security-tracker.debian.org/tracker/CVE-2026-40613
advisories.mageia.org/MGASA-2026-0217.html
Show 21 moreShow less
bugs.mageia.org/show_bug.cgi?id=35430
lists.fedoraproject.org/archives/list/[email protected]/message/HRTRNKXK47ZP6AXDMKTC4HUO7YGKQM4Y
ubuntu.com/security/CVE-2026-40613
cve.org/CVERecord?id=CVE-2026-40613
suse.com/security/cve/CVE-2026-40613
suse.com/security/cve/CVE-2026-43915
suse.com/security/cve/CVE-2026-43994
suse.com/security/cve/CVE-2026-53448
suse.com/security/cve/CVE-2026-53449
suse.com/security/cve/CVE-2026-53450
suse.com/security/cve/CVE-2026-62959
suse.com/security/cve/CVE-2026-65981
suse.com/security/cve/CVE-2026-68552
suse.com/security/cve/CVE-2026-68553
suse.com/security/cve/CVE-2026-68554
suse.com/security/cve/CVE-2026-68555
suse.com/security/cve/CVE-2026-73212
suse.com/security/cve/CVE-2026-73213
suse.com/security/cve/CVE-2026-73214
suse.com/security/cve/CVE-2026-73215
suse.com/security/cve/CVE-2026-73216