{"id":"UBUNTU-CVE-2026-68553","details":"Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.0, an authenticated TURN user can place printf-style format specifiers in the STUN USERNAME or REALM attribute, which passes is_secure_string() validation and is embedded into Redis keys at nine call sites in src/apps/relay/ns_ioalib_engine_impl.c. send_message_to_redis() in src/apps/relay/hiredis_libevent2.c then passes the attacker-controlled key as the format argument to redisAsyncCommand() while supplying only one variadic value, causing hiredis redisvFormatCommand() to read past the va_list. Exploitation can crash the coturn process and terminate active TURN sessions or disclose stack memory into Redis. This issue is fixed in version 4.13.0.","modified":"2026-09-02T16:23:49Z","published":"2026-08-19T21:17:00Z","upstream":["CVE-2026-68553"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-68553"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-68553"},{"type":"REPORT","url":"https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979"},{"type":"REPORT","url":"https://github.com/coturn/coturn/releases/tag/4.13.0"},{"type":"REPORT","url":"https://github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp"}],"affected":[{"package":{"name":"coturn","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/coturn?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.5.4-2","4.5.0.2-3","4.5.0.3-1","4.5.0.3-1build1","4.5.0.3-1ubuntu0.2","4.5.0.3-1ubuntu0.3","4.5.0.3-1ubuntu0.4"],"ecosystem_specific":{"binaries":[{"binary_name":"coturn","binary_version":"4.5.0.3-1ubuntu0.4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-68553.json"}},{"package":{"name":"coturn","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/coturn?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.5.0.6-1ubuntu2","4.5.0.7-1ubuntu1","4.5.0.7-1ubuntu2","4.5.0.7-1ubuntu2.18.04.1","4.5.0.7-1ubuntu2.18.04.2","4.5.0.7-1ubuntu2.18.04.3"],"ecosystem_specific":{"binaries":[{"binary_name":"coturn","binary_version":"4.5.0.7-1ubuntu2.18.04.3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-68553.json"}},{"package":{"name":"coturn","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/coturn?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.5.1.1-1.1build1","4.5.1.1-1.1build2","4.5.1.1-1.1ubuntu0.20.04.1","4.5.1.1-1.1ubuntu0.20.04.2"],"ecosystem_specific":{"binaries":[{"binary_name":"coturn","binary_version":"4.5.1.1-1.1ubuntu0.20.04.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-68553.json"}},{"package":{"name":"coturn","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/coturn?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.5.2-3","4.5.2-3.1~ubuntu22.04.1"],"ecosystem_specific":{"binaries":[{"binary_version":"4.5.2-3.1~ubuntu22.04.1","binary_name":"coturn"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-68553.json"}},{"package":{"name":"coturn","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/coturn?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.6.1-1build1","4.6.1-1build2","4.6.1-1build3","4.6.1-1build4"],"ecosystem_specific":{"binaries":[{"binary_name":"coturn","binary_version":"4.6.1-1build4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-68553.json"}},{"package":{"name":"coturn","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/coturn?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.6.1-2build1","4.6.1-2build2"],"ecosystem_specific":{"binaries":[{"binary_name":"coturn","binary_version":"4.6.1-2build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-68553.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}