Description
Rustls from 0.23.13 before 0.23.45 accepts TLS 1.3 handshake messages at the wrong encryption level when they follow a key-changing message in the same record, because Deframer::aligned does not enforce RFC 8446 record-boundary alignment. A peer or on-path attacker can pack a plaintext EncryptedExtensions with the ServerHello, which rustls accepts unencrypted.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| rustls | rustls | 0.23.13 – < 0.23.45 | 0.23.45 |
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 | 0.23.45+ds-1 | — |
| 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 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | rust +3 | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| crates.io | rustls | >= 0.23.13, < 0.23.45 | 0.23.45 | GHSA-2mjx-qc3c-rqvc |
References
- GitHub Security Advisory (GHSA-2mjx-qc3c-rqvc) vendor-advisory
- Patch Commit patch
- VulnCheck Advisory: Rustls 0.23.13 before 0.23.45 TLS 1.3 Handshake Encryption Level Bypass third-party-advisory