https://db.gcve.eu/rss/recent/all/10 Most recent entries from all 2026-11-08T20:46:08.953004+00:00 Vulnerability-Lookup info@gcve.eu python-feedgen Contains only the most 10 recent entries. https://db.gcve.eu/vuln/ghsa-c8m5-c952-6cm4 GHSA-c8m5-c952-6cm4 — Rustls: Session Debug formatting exposes TLS master secrets and resumption PSKs 2026-11-08T20:46:08.954305+00:00

Affected: crates.io: rustls

### 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 interface already warns that its values are sensitive.

### Details

Derived formatters traverse the session's secret-bearing fields. This conflicts with the project's explicit [key-material redaction policy](https://github.com/rustls/rustls/blob/99f2358cae2954837dbb866faf6727de75489ab9/SECURITY.md#boundary-public-api).

### Proof of concept

Custom `ClientSessionStore` implementations could leak secret data by using the provided `Tls12ClientSessionValue` or `Tls13ClientSessionValue` in a way that triggers its implementation of the `Debug` trait.

### Impact

Such store implementations could leak the master secret for the TLS connection.

### Acknowledgement Thanks to OpenAI [OutboundDisclosures@openai.com](mailto:OutboundDisclosures@openai.com) for the disclosure.