rustls

Rustls is a modern TLS library written in Rust. Status Rustls is used in production at many organizations and projects. We aim to maintain reasonable API surface stability but the API may evolve as we make changes to accommodate new features or performance improvements. We have a roadmap for our...

GHSA-VP88-798V-H67F rustls: ECH rejection can expose buffered application data to authenticated outer server before `ech_required` alert

In rustls 0.23.44 and 0.23.45, application data that a client buffers before the handshake completes is sent to the server even when the server rejects Encrypted Client Hello ECH. When the server rejects ECH, the client completes the handshake with the outer ClientHello and authenticates the serv...

rustls: ECH rejection can expose buffered application data to authenticated outer server before `ech_required` alert

In rustls 0.23.44 and 0.23.45, application data that a client buffers before the handshake completes is sent to the server even when the server rejects Encrypted Client Hello ECH. When the server rejects ECH, the client completes the handshake with the outer ClientHello and authenticates the serv...

rustls: An unauthenticated ServerHello poisons the per-name key-exchange record, so later ClientHellos carry only a classical X25519 share

Summary The client records the server-selected key-exchange group per server name when it processes the ServerHello, before the server is authenticated. A network attacker can answer one connection attempt for a target name with a ServerHello that selects X25519 and close the connection. Later...

GHSA-W44R-93J7-QV28 rustls: An unauthenticated ServerHello poisons the per-name key-exchange record, so later ClientHellos carry only a classical X25519 share

Summary The client records the server-selected key-exchange group per server name when it processes the ServerHello, before the server is authenticated. A network attacker can answer one connection attempt for a target name with a ServerHello that selects X25519 and close the connection. Later...

Rustls: Session Debug formatting exposes TLS master secrets and resumption PSKs

Summary Formatting a client session value with Debug exposes its TLS 1.2 master secret or TLS 1.3 resumption PSK. A custom session store that logs these values can disclose keys to readers of the logs. Ordinary connection and built-in cache diagnostics remain redacted, and the session-store...

GHSA-C8M5-C952-6CM4 Rustls: Session Debug formatting exposes TLS master secrets and resumption PSKs

Summary Formatting a client session value with Debug exposes its TLS 1.2 master secret or TLS 1.3 resumption PSK. A custom session store that logs these values can disclose keys to readers of the logs. Ordinary connection and built-in cache diagnostics remain redacted, and the session-store...

GHSA-H2V8-394M-P7VV Rustls: Brotli certificate decompression can allocate an attacker-controlled amount of memory up to 1 GiB before authentication.

Summary The built-in but disabled by default Brotli certificate decoder bounds the output buffer but accepts an input-selected history window. A header of five bytes can specify a 1 GiB window allocation. A peer can abort a process whose allocator cannot satisfy that request. A client must enable...

Rustls: Brotli certificate decompression can allocate an attacker-controlled amount of memory up to 1 GiB before authentication.

Summary The built-in but disabled by default Brotli certificate decoder bounds the output buffer but accepts an input-selected history window. A header of five bytes can specify a 1 GiB window allocation. A peer can abort a process whose allocator cannot satisfy that request. A client must enable...

Use-after-free of caller-owned server name in client connection constructors

In rustls-ffi 0.12.0 through 0.15.6, rustlsclientconnectionnew and rustlsclientconnectionnewalpn retained a reference to the caller's servername 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...

rustls-ffi -- Read after free

The RusTLS project reports: functions retained a reference to the caller's servername 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...

Rocky Linux 10.2 [CIQ] Security Update: rust-sequoia-sq-debugsource / sequoia-sq / sequoia-sq-debuginfo Multiple Vulnerabilities (crlsa-2026_85848)

The Rocky Linux 10.2 host has packages installed that are affected by multiple vulnerabilities as referenced in the CIQ crlsa-202685848 advisory. hickory-resolver: hickory-resolver: DNSSEC validation bypass allows forged DNS records CVE-2026-93657 rustls-webpki: rustls-webpki: Denial of Service v...

Fedora 43 : rust-rustls-webpki / rust-webpki-root-certs / rust-webpki-roots (2026-1ffbf97eba)

The remote Fedora 43 host has packages installed that are affected by a vulnerability as referenced in the FEDORA-2026-1ffbf97eba advisory. - Update the rustls-webpki crate to version 0.103.16. - Update the webpki-roots and webpki-root-certs crates to version 1.0.10. This addresses security...

RLSA-2026:85848 Important: rust-sequoia-sq security update

Command-line frontends for Sequoia. Security Fixes: hickory-resolver: hickory-resolver: DNSSEC validation bypass allows forged DNS records CVE-2026-93657 rustls-webpki: rustls-webpki: Denial of Service via crafted Certificate Revocation List CVE-2026-93599 For more details about the security...

rust-sequoia-sq security update

An update is available for rust-sequoia-sq. This update affects Rocky Linux 10. A Common Vulnerability Scoring System CVSS base score, which gives a detailed severity rating, is available for each vulnerability from the CVE list Command-line frontends for Sequoia. Security Fixes: hickory-resolver...

AlmaLinux 10 : rust-sequoia-sq (ALSA-2026:85848)

The remote AlmaLinux 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the ALSA-2026:85848 advisory. hickory-resolver: hickory-resolver: DNSSEC validation bypass allows forged DNS records CVE-2026-93657 rustls-webpki: rustls-webpki: Denial of Service vi...

RockyLinux 10 : rust-sequoia-sq (RLSA-2026:85848)

The remote RockyLinux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:85848 advisory. hickory-resolver: hickory-resolver: DNSSEC validation bypass allows forged DNS records CVE-2026-93657 rustls-webpki: rustls-webpki: Denial of Service v...

Fedora 44 : rust-rustls-webpki / rust-webpki-root-certs / rust-webpki-roots (2026-8eeffa4c43)

The remote Fedora 44 host has packages installed that are affected by a vulnerability as referenced in the FEDORA-2026-8eeffa4c43 advisory. - Update the rustls-webpki crate to version 0.103.16. - Update the webpki-roots and webpki-root-certs crates to version 1.0.10. This addresses security...

a11ywatch_cli (>=0.0.26, <=0.6.51), abstractapi (>=0.1.0, <=0.1.3) +631 more potentially affected by CVE-2026-111943 via rustls-webpki (>=0.100.3, <=0.101.7)

rustls-webpki CARGO version =0.100.3, =0.0.26, =0.1.0, =0.6.0, =0.6.0, =0.1.0, =0.2.0, =1.0.0, =0.1.0, =0.2.0, =0.1.0, =0.4.0, =0.1.0, =0.1.3 and more Source cves: CVE-2026-111943 Source advisory: OSV:RUSTSEC-2026-0382...

Important: Red Hat Security Advisory: rust-sequoia-sq security update

An update for rust-sequoia-sq is now available for Red Hat Enterprise Linux 10. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System CVSS base score, which gives a detailed severity rating, is available for each vulnerabili...