RUSTSEC-2026-0285

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Source

https://rustsec.org/advisories/RUSTSEC-2026-0285

Import Source

https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0285.json

JSON Data

https://api.osv.dev/v1/vulns/RUSTSEC-2026-0285

Aliases

GHSA-2mjx-qc3c-rqvc

Published

2026-09-14T12:00:00Z

Modified

2026-09-14T16:15:03Z

Severity

5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator

Summary

TLS 1.3 handshake messages incorrectly accepted across encryption level boundaries

Details

Rustls accepted TLS 1.3 handshake messages sent at the wrong encryption level when they followed a key-changing message in the same record. For example, a plaintext EncryptedExtensions message packed into the same record as the ServerHello was accepted.

RFC 8446 section 5.1 requires that handshake messages do not span key changes, and that implementations terminate the connection with an "unexpected_message" alert if they do.

The handshake transcript is still authenticated, so a network-position attacker cannot use this to alter or complete a handshake; the practical effect is that a peer could send handshake messages that should be encrypted in plaintext without rustls rejecting the connection.

This is functionally the same bug as Go's GO-2026-4340 (CVE-2025-61730).

Database specific

{
    "license": "CC0-1.0"
}

References

Affected packages

crates.io / rustls

Package

Name: rustls; View open source insights on deps.dev
Purl: pkg:cargo/rustls

Affected ranges

Type: SEMVER
Events: Introduced

0.23.13

Fixed

0.23.45

Ecosystem specific

{
    "affected_functions": null,
    "affects": {
        "arch": [],
        "functions": [],
        "os": []
    }
}