{"id":"CVE-2026-68553","state":"PUBLISHED","title":"Coturn: Format String Injection via TURN USERNAME/REALM into hiredis Redis Command","description":"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.","publishedAt":"2026-08-19T20:37:42.319Z","updatedAt":"2026-08-20T19:48:45.809Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["coturn coturn"],"affected":[{"vendor":"coturn","product":"coturn","versions":[{"version":"< 4.13.0","status":"affected"}]}],"references":["https://github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp","https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979","https://github.com/coturn/coturn/releases/tag/4.13.0"],"weaknesses":["CWE-134"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68553.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68553","state":"PUBLISHED","datePublished":"2026-08-19T20:37:42.319Z","dateUpdated":"2026-08-20T19:48:45.809Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-30T19:56:44.102Z"},"containers":{"cna":{"title":"Coturn: Format String Injection via TURN USERNAME/REALM into hiredis Redis Command","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"coturn","product":"coturn","versions":[{"version":"< 4.13.0","status":"affected"}]}],"references":[{"url":"https://github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp","name":"https://github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979","name":"https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979","tags":["x_refsource_MISC"]},{"url":"https://github.com/coturn/coturn/releases/tag/4.13.0","name":"https://github.com/coturn/coturn/releases/tag/4.13.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.1,"baseSeverity":"HIGH","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-134","lang":"en","description":"CWE-134: Use of Externally-Controlled Format String","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-19T20:37:42.319Z"},"source":{"advisory":"GHSA-4g7c-p5wg-j4hp","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-20T19:48:40.817549Z","id":"CVE-2026-68553","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-20T19:48:45.809Z"}}]}}}