Upstream information

CVE-2026-27624 at MITRE

Description

Coturn is a free open source implementation of TURN and STUN Server. Coturn is commonly configured to block loopback and internal ranges using "denied-peer-ip" and/or default loopback restrictions. CVE-2020-26262 addressed bypasses involving "0.0.0.0", "[::1]" and "[::]", but IPv4-mapped IPv6 is not covered. When sending a "CreatePermission" or "ChannelBind" request with the "XOR-PEER-ADDRESS" value of "::ffff:127.0.0.1", a successful response is received, even though "127.0.0.0/8" is blocked via "denied-peer-ip". The root cause is that, prior to the updated fix implemented in version 4.9.0, three functions in "src/client/ns_turn_ioaddr.c" do not check "IN6_IS_ADDR_V4MAPPED". "ioa_addr_is_loopback()" checks "127.x.x.x" (AF_INET) and "::1" (AF_INET6), but not "::ffff:127.0.0.1." "ioa_addr_is_zero()" checks "0.0.0.0" and "::", but not "::ffff:0.0.0.0." "addr_less_eq()" used by "ioa_addr_in_range()" for "denied-peer-ip" matching: when the range is AF_INET and the peer is AF_INET6, the comparison returns 0 without extracting the embedded IPv4. Version 4.9.0 contains an updated fix to address the bypass of the fix for CVE-2020-26262.

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having important severity.

CVSS v3 Scores
CVSS detail CNA (GitHub) National Vulnerability Database
Base Score 7.2 6.5
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack Vector Network Network
Attack Complexity Low Low
Privileges Required None None
User Interaction None None
Scope Changed Unchanged
Confidentiality Impact Low Low
Integrity Impact Low Low
Availability Impact None None
CVSSv3 Version 3.1 3.1
SUSE Bugzilla entry: 1180764 [RESOLVED / FIXED]

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References
SUSE Package Hub 15 SP6
  • coturn >= 4.9.0-bp156.2.3.1
  • coturn-devel >= 4.9.0-bp156.2.3.1
  • coturn-utils >= 4.9.0-bp156.2.3.1
Patchnames:
openSUSE-2026-143
openSUSE Leap 15.6
  • coturn >= 4.9.0-bp156.2.3.1
  • coturn-devel >= 4.9.0-bp156.2.3.1
  • coturn-utils >= 4.9.0-bp156.2.3.1
Patchnames:
openSUSE-2026-143
openSUSE Tumbleweed
  • coturn >= 4.9.0-1.1
  • coturn-devel >= 4.9.0-1.1
  • coturn-utils >= 4.9.0-1.1
Patchnames:
openSUSE-Tumbleweed-2026-10375


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products past their end of life and not receiving proactive updates anymore.
SUSE Package Hub 15 SP6 coturn Released


SUSE Timeline for this CVE

CVE page created: Tue Jan 12 09:18:07 2021
CVE page last modified: Mon Apr 20 17:32:56 2026