{"id":"RUSTSEC-2026-0413","aliases":["GHSA-rc3f-4j82-cmrg"],"title":"Use-after-free of caller-owned server name in client connection constructors","summary":"Use-after-free of caller-owned server name in client connection constructors","severity":"none","vendor":"rustls-ffi","product":"rustls-ffi","ecosystem":"rust","affected":["rustls-ffi >= 0.12.0, < 0.15.7"],"patched":["rustls-ffi 0.15.7"],"published":"2026-10-26","updated":"2026-10-27","sourceUpdated":"2026-10-27T10:15:12.837053276Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/RUSTSEC-2026-0413","references":[{"url":"https://crates.io/crates/rustls-ffi"},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0413.html"},{"url":"https://github.com/rustls/rustls-ffi/releases/tag/v/0.15.7"}],"tags":["osv","rust"],"ingestedAt":"2026-10-27T16:20:12.122Z","slug":"RUSTSEC-2026-0413","body":"## Overview\n\nIn rustls-ffi 0.12.0 through 0.15.6, `rustls_client_connection_new()` and\n`rustls_client_connection_new_alpn()` retained a reference to the caller's\n`server_name` buffer after returning, rather than copying it. The API\ndocumentation did not require the buffer to outlive the call and as a result\nif the caller freed or reused the buffer, later TLS processing read freed\nmemory.\n\nClients that free or reuse the `server_name` buffer after the constructor\nreturns are affected. This is most likely for language bindings that pass\ntemporary strings. Callers that keep the `server_name` buffer alive for the\nlifetime of the `rustls_client_config` are not affected.\n\nVersions 0.12.0 through 0.15.6 are affected. Version 0.15.7+ changed these APIs\nto copy the input buffer.\n\n## Affected packages\n\n- `rustls-ffi >= 0.12.0, < 0.15.7`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `rustls-ffi 0.15.7`","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}