{"id":"CVE-2026-68553","summary":"Coturn: Format String Injection via TURN USERNAME/REALM into hiredis Redis Command","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.","aliases":["GHSA-4g7c-p5wg-j4hp"],"modified":"2026-08-20T11:47:22.632643083Z","published":"2026-08-19T20:37:42.319Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-134"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68553.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68553.json"},{"type":"FIX","url":"https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979"},{"type":"WEB","url":"https://github.com/coturn/coturn/releases/tag/4.13.0"},{"type":"ADVISORY","url":"https://github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68553"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/coturn/coturn","events":[{"introduced":"0"},{"fixed":"bd02141ad865830fdea420ca0c803edf5ba8240c"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"4.13.0"}],"source":"AFFECTED_FIELD"}}],"versions":["docker/4.12.0-r0","4.12.0","docker/4.11.0-r0","4.11.0","docker/4.10.0-r1","docker/4.10.0-r0","4.10.0","docker/4.9.0-r0","4.9.0","docker/4.8.0-r1","docker/4.8.0-r0","4.8.0","docker/4.7.0-r4","docker/4.7.0-r3","docker/4.7.0-r2","docker/4.7.0-r1","docker/4.7.0-r0","4.7.0","docker/4.6.3-r3","docker/4.6.3-r2","docker/4.6.3-r1","docker/4.6.3-r0","4.6.3","docker/4.6.2-r13","docker/4.6.2-r12","docker/4.6.2-r11","docker/4.6.2-r10","docker/4.6.2-r9","docker/4.6.2-r8","docker/4.6.2-r7","docker/4.6.2-r6","docker/4.6.2-r5","docker/4.6.2-r4","docker/4.6.2-r3","docker/4.6.2-r2","docker/4.6.2-r1","docker/4.6.2-r0","4.6.2","docker/4.6.1-r3","docker/4.6.1-r2","docker/4.6.1-r1","docker/4.6.1-r0","docker/4.6.0-r1","docker/4.6.0-r0","4.6.0","docker/4.5.2-r14","docker/4.5.2-r13","docker/4.5.2-r12","docker/4.5.2-r11","docker/4.5.2-r10","docker/4.5.2-r9","docker/4.5.2-r8","docker/4.5.2-r7","docker/4.5.2-r6","docker/4.5.2-r0","4.5.2","4.5.1.3","4.5.1.2","4.5.1.1","4.5.1.0","4.5.0.7","4.5.0.6","4.5.0.5","4.5.0.4","4.5.0.3","4.5.0.2","4.5.0.1","4.4.5.4","4.4.5.3"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/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"}]}