{"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":"2026-09-11T08:38:45.287202Z","published":"2026-08-19T20:37:42.319Z","related":["openSUSE-SU-2026:11617-1"],"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":"WEB","url":"https://github.com/coturn/coturn/releases/tag/4.13.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68553.json"},{"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"},{"type":"FIX","url":"https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/coturn/coturn","events":[{"introduced":"0"},{"fixed":"8fa38032bb4751e11e072d65a8eca3c06c950979"},{"fixed":"bd02141ad865830fdea420ca0c803edf5ba8240c"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"4.13.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"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/osv-test-cve-osv-conversion/osv-output/CVE-2026-68553.json","vanir_signatures_modified":"2026-09-11T08:38:45Z","vanir_signatures":[{"deprecated":false,"digest":{"function_hash":"32006592092507274028534772350769914051","length":796},"id":"CVE-2026-68553-3a277461","signature_type":"Function","signature_version":"v1","source":"https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979","target":{"file":"src/apps/relay/hiredis_libevent2.c","function":"send_message_to_redis"}},{"digest":{"line_hashes":["7008343823719524246775466739624232925","164326885605320067784527460612092456532","232870857423825754736201196399573553534","277418429990215895891544659365328130642","223364290905603362512525812524757961546","220078280621677000621861036440754135183","305380475780737583159728793496363930162","48689273660248281508479029777550020834","44023742355221023370947280242239325189","224902225402318080177491273361284234280","277312745928741404452372917234012353961","83115179930311507019911035090996567248","257459578524637863462180920100211572474","200770991417903771080054953921960616642"],"threshold":0.9},"id":"CVE-2026-68553-88499476","signature_type":"Line","signature_version":"v1","source":"https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979","target":{"file":"src/apps/relay/hiredis_libevent2.c"},"deprecated":false}]}}],"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"}]}