Coturn: MOBILITY-TICKET session-resume authorization bypass allows cross-user TURN allocation takeover
Summary
| CVE | CVE-2026-65981 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-31 21:17:31 UTC |
| Updated | 2026-07-31 21:17:31 UTC |
| Description | Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.15.0, a server using --mobility authenticates a resumed REFRESH request with the resuming user's credentials but does not verify that identity against the original allocation owner, allowing an authenticated attacker who obtains a victim MOBILITY-TICKET to receive and inject relayed traffic and consume the victim's quota. In the handle_turn_refresh resume branch, the victim allocation (orig_ss) is located solely by the attacker-controlled mobile id, and credentials are only adopted (via copy_auth_parameters) when the resuming session is unauthenticated. Because the attacker's session already has hmackey_set set to 1 from its own prior authentication (which is never reset for long-term-credential sessions), the credential copy is skipped and check_stun_auth validates the REFRESH against the attacker's own identity rather than the allocation owner's. This issue is fixed in version 4.15.0. |
Risk And Classification
Primary CVSS: v3.1 7.1 HIGH from [email protected]
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
Problem Types: CWE-639 | CWE-639 CWE-639: Authorization Bypass Through User-Controlled Key
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L |
| 3.1 | CNA | DECLARED | 7.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
LowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/coturn/coturn/security/advisories/GHSA-69wx-x7x6-pjj8 | [email protected] | github.com | |
| github.com/coturn/coturn/commit/37df0513168f830a7c9ce0a411db0300fa182f05 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.