Every CVE Search/ Get API key

CVE-2026-65981

Coturn: MOBILITY-TICKET session-resume authorization bypass allows cross-user TURN allocation takeover

7.1 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
High
Privileges needed
Low
User interaction
None

What an attacker can affect

Confidentiality
High
Integrity
High
Availability
Low

Exploit likelihood

0.39%Up 0.1 points since Aug 1, 2026
90%50%10%1%

What each source reports

CVE List Score used 7.1

Coturn: MOBILITY-TICKET session-resume authorization bypass allows cross-user TURN allocation takeover

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.

Record
CVE-2026-65981
CVSS 3.1
7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
Weakness
CWE-639
Updated
2026-11-02
EUVDEUVD-2026-51651 7.1

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.

Record
EUVD-2026-51651
CVSS 3.1
7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
Updated
2026-11-02
NVD 7.1

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.

Record
CVE-2026-65981
CVSS 3.1
7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
Weakness
CWE-639
Updated
2026-11-02
OSV 7.1

Coturn: MOBILITY-TICKET session-resume authorization bypass allows cross-user TURN allocation takeover

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.

Record
CVE-2026-65981
CVSS 3.1
7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
Weakness
CWE-639
Updated
2026-11-02
OSVDEBIAN-CVE-2026-65981 7.1

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.

Record
DEBIAN-CVE-2026-65981
CVSS 3.1
7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
Updated
2026-11-02
OSVUBUNTU-CVE-2026-65981 7.1

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.

Record
UBUNTU-CVE-2026-65981
CVSS 3.1
7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
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

Affected packages
PackageAffectedFixed
coturn
Debian: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
coturn
Debian:13
All versions, plus listed versions
4.12.0-14.14.0-14.15.0-14.18.0-14.6.1-2
None known
coturn
Debian:14
before 4.15.0-1, plus listed versions
4.12.0-14.14.0-14.6.1-2
4.15.0-1
coturn
Ubuntu: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
coturn
Ubuntu: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
coturn
Ubuntu: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
coturn
Ubuntu:22.04:LTS
All versions, plus listed versions
4.5.2-34.5.2-3.1~ubuntu22.04.1
None known
coturn
Ubuntu:24.04:LTS
All versions, plus listed versions
4.6.1-1build14.6.1-1build24.6.1-1build34.6.1-1build4
None known
coturn
Ubuntu: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
coturn
Ubuntu:26.04:LTS
All versions, plus listed versions
4.6.1-2build14.6.1-2build2
None known
coturn
openSUSE:Tumbleweed
From an advisory covering 17 CVEs
before 4.17.2-1.1
4.17.2-1.1

History

History
RecordedChangedSources
affected, facts
aliases, publishedEUVD
first indexedCVE List, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-65981 is a high vulnerability (CVSS 7.1) in Coturn, published July 31, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.39%, the 33rd percentile. Fixed in coturn 4.15.0-1.

References

Show 18 moreShow less
MoveEnter Open