Description
rustls 0.23.44 and 0.23.45 contain an information disclosure vulnerability that sends application data buffered before the handshake completes to the client-facing server when Encrypted Client Hello is rejected. Because start_traffic() queues plaintext from ClientConnection::writer() before sending the ech_required alert, the authenticated public_name server receives data intended for the inner server.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| rustls | rustls | 0.23.44 – < 0.23.46 | 0.23.46 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | rust-rustls | No fix yet | — |
| Debian 13 | rust-rustls | No fix yet | — |
| Debian 12 | rust-rustls | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | rust-rustls | No fix yet | — |
| Ubuntu 26.04 LTS | rust-rustls | No fix yet | — |
| Ubuntu 24.04 LTS | rust-rustls | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| crates.io | rustls | >= 0.23.44, < 0.23.46 | 0.23.46 | GHSA-vp88-798v-h67f |
| crates.io | rustls | >= 0.24.0-dev.1, < 0.24.0-dev.2 | 0.24.0-dev.2 | GHSA-vp88-798v-h67f |
References
- GitHub Security Advisory (GHSA-vp88-798v-h67f) vendor-advisory
- VulnCheck Advisory: rustls 0.23.44 and 0.23.45 ECH Rejection Application Data Disclosure third-party-advisory