Summary
Rust XCB xcb::Connection::connecttofd* functions violate I/O safety
The API of xcb::Connection has constructors which allow an arbitrary RawFd to be used as a socket connection. On either failure of these constructors or on the drop of Connection, it closes the associated file descriptor. Thus, a program which uses an OwnedFd (such as a UnixStream) as the file descriptor can close the file descriptor and continue to attempt using it or close an already-closed file descriptor, violating I/O safety.
Starting in version 1.6.0, xcb provides Connection::connect_with_fd and Connection::connect_with_fd_and_extensions as safe alternatives and deprecates the problematic functions.
Impact
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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Frequently Asked Questions
- What is GHSA-655H-HG88-5QMF? GHSA-655H-HG88-5QMF is a low-severity security vulnerability in xcb (rust), affecting versions < 1.6.0. It is fixed in 1.6.0.
- Which versions of xcb are affected by GHSA-655H-HG88-5QMF? xcb (rust) versions < 1.6.0 is affected.
- Is there a fix for GHSA-655H-HG88-5QMF? Yes. GHSA-655H-HG88-5QMF is fixed in 1.6.0. Upgrade to this version or later.
- Is GHSA-655H-HG88-5QMF exploitable, and should I be worried? Whether GHSA-655H-HG88-5QMF is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-655H-HG88-5QMF is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-655H-HG88-5QMF? Upgrade
xcbto 1.6.0 or later.