{"id":"CVE-2026-62959","state":"PUBLISHED","title":"Coturn: Pre-authentication heap memory disclosure in ACME redirect (`try_acme_redirect`)","description":"Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.","publishedAt":"2026-07-31T19:57:06.394Z","updatedAt":"2026-07-31T23:34:33.361Z","severity":{"score":8.2,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["coturn coturn"],"affected":[{"vendor":"coturn","product":"coturn","versions":[{"version":">= 4.5.2, < 4.15.0","status":"affected"}]}],"references":["https://github.com/coturn/coturn/security/advisories/GHSA-m23x-5qf5-988g","https://github.com/coturn/coturn/pull/1965","https://github.com/coturn/coturn/commit/960835886692fa04cf63ddd970c3f330740c87f4","https://github.com/coturn/coturn/releases/tag/4.15.0"],"weaknesses":["CWE-125","CWE-195"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/62xxx/CVE-2026-62959.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-62959","state":"PUBLISHED","datePublished":"2026-07-31T19:57:06.394Z","dateUpdated":"2026-07-31T23:34:33.361Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-14T22:32:17.732Z"},"containers":{"cna":{"title":"Coturn: Pre-authentication heap memory disclosure in ACME redirect (`try_acme_redirect`)","descriptions":[{"lang":"en","value":"Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0."}],"affected":[{"vendor":"coturn","product":"coturn","versions":[{"version":">= 4.5.2, < 4.15.0","status":"affected"}]}],"references":[{"url":"https://github.com/coturn/coturn/security/advisories/GHSA-m23x-5qf5-988g","name":"https://github.com/coturn/coturn/security/advisories/GHSA-m23x-5qf5-988g","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/coturn/coturn/pull/1965","name":"https://github.com/coturn/coturn/pull/1965","tags":["x_refsource_MISC"]},{"url":"https://github.com/coturn/coturn/commit/960835886692fa04cf63ddd970c3f330740c87f4","name":"https://github.com/coturn/coturn/commit/960835886692fa04cf63ddd970c3f330740c87f4","tags":["x_refsource_MISC"]},{"url":"https://github.com/coturn/coturn/releases/tag/4.15.0","name":"https://github.com/coturn/coturn/releases/tag/4.15.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.2,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","description":"CWE-125: Out-of-bounds Read","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-195","lang":"en","description":"CWE-195: Signed to Unsigned Conversion Error","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-31T19:57:06.394Z"},"source":{"advisory":"GHSA-m23x-5qf5-988g","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/coturn/coturn/security/advisories/GHSA-m23x-5qf5-988g","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-31T23:34:10.861030Z","id":"CVE-2026-62959","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-31T23:34:33.361Z"}}]}}}