{"schemaVersion":3,"id":"CVE-2026-68553","aliases":["UBUNTU-CVE-2026-68553","DEBIAN-CVE-2026-68553"],"status":"published","duplicateOf":null,"title":null,"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.","dates":{"published":"2026-08-19T20:37:42.319Z","modified":"2026-08-20T19:48:45.809Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.1,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":7.1,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":7.1,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H","exploitability":7.2,"impact":7,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","score":7.1,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H","exploitability":7.2,"impact":7,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":7.1,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.0048,"percentile":0.40367,"severity":"low","asOf":"2026-10-21T00:00:00.000Z","change":{"pp":0.13499999999999995,"baselineDate":"2026-09-21T00:00:00.000Z","baselineScore":0.00345},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.0048,"percentile":0.40367}],"last30":[{"date":"2026-09-21T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00345,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.0048,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.0048,"percentile":0.40367}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-134","name":"Use of Externally-Controlled Format String","description":"The product uses a function that accepts a format string as an argument, but the format string originates from an external source.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/134.html"}],"affected":[{"vendor":"coturn","product":"coturn","name":"coturn","label":"coturn","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 4.13.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 4.13.0","eol":null,"hubHref":"/vendor/coturn/coturn"},{"vendor":"debian","product":"coturn","name":"coturn","label":"coturn","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/coturn","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null},{"text":"< 4.14.0-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"All versions (No fix recorded) | < 4.14.0-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"coturn","name":"coturn","label":"coturn","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/coturn","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null}],"affectedCount":3,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp","label":"github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp","hostname":"github.com","tags":["X Refsource CONFIRM","REPORT"]},{"url":"https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979","label":"github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979","hostname":"github.com","tags":["X Refsource MISC","REPORT"]},{"url":"https://github.com/coturn/coturn/releases/tag/4.13.0","label":"github.com/coturn/coturn/releases/tag/4.13.0","hostname":"github.com","tags":["X Refsource MISC","REPORT"]},{"url":"https://ubuntu.com/security/CVE-2026-68553","label":"ubuntu.com/security/CVE-2026-68553","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-68553","label":"www.cve.org/CVERecord?id=CVE-2026-68553","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-68553","label":"security-tracker.debian.org/tracker/CVE-2026-68553","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["OPENSUSE-SU-2026:11617-1"],"duplicates":[],"related":["OPENSUSE-SU-2026:11617-1"]},"timeline":[{"kind":"published","date":"2026-08-19T20:37:42.319Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-08-20T19:48:45.809Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":28,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-22T12:35:33.811Z","stale":false,"partial":false}}