GHSA-rc3f-4j82-cmrg
Use-after-free of caller-owned server name in client connection constructors
In rustls-ffi 0.12.0 through 0.15.6, rustls_client_connection_new() and
rustls_client_connection_new_alpn() retained a reference to the caller's
server_name buffer after returning, rather than copying it. The API
documentation did not require the buffer to outlive the call and as a result
if the caller freed or reused the buffer, later TLS processing read freed
memory.
Clients that free or reuse the server_name buffer after the constructor
returns are affected. This is most likely for language bindings that pass
temporary strings. Callers that keep the server_name buffer alive for the
lifetime of the rustls_client_config are not affected.
Versions 0.12.0 through 0.15.6 are affected. Version 0.15.7+ changed these APIs to copy the input buffer.
What each source reports
OSVRUSTSEC-2026-0413No score
Use-after-free of caller-owned server name in client connection constructors
In rustls-ffi 0.12.0 through 0.15.6, rustls_client_connection_new() and
rustls_client_connection_new_alpn() retained a reference to the caller's
server_name buffer after returning, rather than copying it. The API
documentation did not require the buffer to outlive the call and as a result
if the caller freed or reused the buffer, later TLS processing read freed
memory.
Clients that free or reuse the server_name buffer after the constructor
returns are affected. This is most likely for language bindings that pass
temporary strings. Callers that keep the server_name buffer alive for the
lifetime of the rustls_client_config are not affected.
Versions 0.12.0 through 0.15.6 are affected. Version 0.15.7+ changed these APIs to copy the input buffer.
- Record
RUSTSEC-2026-0413- Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
rustls-fficrates.io | 0.12.0 up to 0.15.7 | 0.15.7 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
GHSA-rc3f-4j82-cmrg is a vulnerability with no CVSS score yet in rustls-ffi, published October 26, 2026. No source lists public exploit code. Fixed in rustls-ffi 0.15.7.