Complete the IP-host certificate identity fix from v0.47.0 for the
Mbed TLS and wolfSSL backends. An IP-literal host is now authenticated
only via a matching iPAddress SAN, never via the certificate's Common
Name (RFC 9110) — matching what the OpenSSL backend already enforces
through X509_check_ip. Previously these backends fell back to the CN
when no IP SAN matched, and recognized IPv4 only; now IPv6 (16-byte)
iPAddress SANs are matched as well, and the CN fallback is skipped for
both IPv4 and IPv6 literal hosts (#2476)
Improvements
Replace the strtod-based from_chars for double with a hand-written,
locale-independent parser. The only double parsed by the library is the
HTTP quality value; strtod reads the decimal separator from the global C
locale, so an embedder calling setlocale(LC_ALL, "") into a
comma-decimal locale would mis-parse q-values. The new parser always
treats . as the decimal separator and is allocation-free (Fix #2475)
Fix OpenSSL 4.0 deprecation warnings: fetch CA store objects via the
thread-safe X509_STORE_get1_objects() (OpenSSL 3.3+) and extract the
subject CN via X509_NAME_get_index_by_NID()/X509_NAME_get_entry()
instead of the deprecated X509_STORE_get0_objects() and
X509_NAME_get_text_by_NID(). Older OpenSSL, BoringSSL, and LibreSSL keep
using the get0 path. Verified warning-free against OpenSSL 4.0.1, 3.6.2,
and 3.0
Behavior changes
decode_query_component() now uses strict hex parsing for
percent-escapes, consistent with decode_uri_component() and
decode_path_component(). A % followed by non-hex characters (e.g. a sign
or whitespace such as %-1, %+5, % 5) is passed through literally instead
of being accepted as a valid escape (#2472)
Update to 0.47.0 (#2481109, CVE-2026-46527, CVE-2026-45372, CVE-2026-45352)
Security fixes
Fix TLS certificate chain verification bypass for IP-literal hosts on the Mbed TLS and wolfSSL backends: with server certificate verification enabled, SSLClient skipped chain validation entirely (any untrusted certificate with a matching IP SAN was accepted), and WebSocketClient on Mbed TLS skipped verification altogether. Chain verification now stays enabled for IP hosts, and certificate identity is verified post-handshake against IP SANs on all backends. SNI is no longer sent for IP hosts on Mbed TLS and wolfSSL, per RFC 6066 (CVE-2026-54919)
New features
Add Server::set_start_handler(): a callback invoked when the server is ready to accept connections, useful when running the server in a background thread (#2467)
Add Client/SSLClient/WebSocketClient::enable_system_ca(bool) to opt into loading system CA certificates alongside a custom CA. The default is unchanged: a custom CA remains exclusive. The setting carries over to clients created for HTTPS redirects (#2471)
Add WebSocketClient::set_hostname_addr_map() to connect to a specific IP address while keeping the original hostname for the handshake and certificate verification (#2463)
Behavior changes
The request body is now read after route matching and the pre-request handler, so both the regular handler and ContentReader paths behave the same: route matching → pre-request handler → body read → handler. A request rejected by the pre-request handler (e.g. failed per-route authentication via req.matched_route) no longer buffers the body at all. Note: code that referenced req.body or body-derived form fields inside the pre-request handler will now see an empty body; inspect headers, path, query parameters, or matched_route instead
WebSocketClient with a custom CA no longer merges system CA certificates (it previously always merged them). This matches SSLClient behavior; call enable_system_ca(true) to load system CA certificates alongside the custom CA
Range request headers are now ignored for streaming responses of unknown length instead of producing an invalid response (#2465)
Bug fixes
Fix SSLClient::set_ca_cert_store() breaking custom-CA exclusivity: system CA certificates were silently merged into the user-provided store, broadening the trust set. Also fix Client::load_ca_cert_store() not carrying CA certificates over to clients created for HTTPS redirects
Fix WebSocketClient dropping the query string from the URL during the upgrade handshake, so query parameters (e.g. auth tokens) are sent (#2468)
Fix a use-after-free when reconnecting a WebSocketClient after set_ca_cert_store(), and a memory leak in the Mbed TLS and wolfSSL set_ca_cert_store() backends
Fix MSVC warning C4309 (truncation of constant value) in SHA padding code (#2464)
Cast to unsigned char before ctype calls in is_hex and is_token_char to avoid undefined behavior with negative char values (#2469)
This update has been submitted for testing by pemensik.
This update's test gating status has been changed to 'ignored'.
This update has been pushed to testing.
This update has been submitted for stable by bodhi.
This update has been pushed to stable.