CVE-2026-62959
Coturn: Pre-authentication heap memory disclosure in ACME redirect (`try_acme_redirect`)
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
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
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.2
Coturn: Pre-authentication heap memory disclosure in ACME redirect (`try_acme_redirect`)
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
- Record
CVE-2026-62959- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-125, CWE-195
- Updated
- 2026-11-02
EUVDEUVD-2026-51627
8.2
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
- Record
EUVD-2026-51627- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
NVD
8.2
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
- Record
CVE-2026-62959- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-125, CWE-195
- Updated
- 2026-11-02
OSV
8.2
Coturn: Pre-authentication heap memory disclosure in ACME redirect (`try_acme_redirect`)
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
- Record
CVE-2026-62959- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-125, CWE-195
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-62959
8.2
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
- Record
DEBIAN-CVE-2026-62959- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-62959
8.2
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
- Record
UBUNTU-CVE-2026-62959- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - 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 |
|---|---|---|
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 4.15.0-1, plus listed versions 4.12.0-14.14.0-14.6.1-2 |
4.15.0-1 |
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 |
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: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 | ||
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-62959 is a high vulnerability (CVSS 8.2) in Coturn, published July 31, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.52%, the 44th percentile. Fixed in coturn 4.15.0-1.
References
github.com/coturn/coturn/security/advisories/GHSA-m23x-5qf5-988g
github.com/coturn/coturn/pull/1965
github.com/coturn/coturn/commit/960835886692fa04cf63ddd970c3f330740c87f4
github.com/coturn/coturn/releases/tag/4.15.0
github.com/CVEProject/cvelistV5/tree/main/cves/2026/62xxx/CVE-2026-62959.json
nvd.nist.gov/vuln/detail/CVE-2026-62959
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security-tracker.debian.org/tracker/CVE-2026-62959
ubuntu.com/security/CVE-2026-62959
cve.org/CVERecord?id=CVE-2026-62959
suse.com/security/cve/CVE-2026-40613
suse.com/security/cve/CVE-2026-43915
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suse.com/security/cve/CVE-2026-53450
suse.com/security/cve/CVE-2026-62959
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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