Summary
bumpalo has use-after-free due to a lifetime error in Vec::into_iter()
In affected versions of this crate, the lifetime of the iterator produced by Vec::into_iter() is not constrained to the lifetime of the Bump that allocated the vector's memory. Using the iterator after the Bump is dropped causes use-after-free accesses.
The following example demonstrates memory corruption arising from a misuse of this unsoundness.
use bumpalo::{collections::Vec, Bump};
fn main() {
let bump = Bump::new();
let mut vec = Vec::new_in(&bump);
vec.extend([0x01u8; 32]);
let into_iter = vec.into_iter();
drop(bump);
for _ in 0..100 {
let reuse_bump = Bump::new();
let _reuse_alloc = reuse_bump.alloc([0x41u8; 10]);
}
for x in into_iter {
print!("0x{:02x} ", x);
}
println!();
}
The issue was corrected in version 3.11.1 by adding a lifetime to the IntoIter type, and updating the signature of Vec::into_iter() to constrain this lifetime.
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.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is GHSA-F85W-WVC7-CRWC? GHSA-F85W-WVC7-CRWC is a medium-severity security vulnerability in bumpalo (rust), affecting versions >= 1.1.0, < 3.11.1. It is fixed in 3.11.1.
- Which versions of bumpalo are affected by GHSA-F85W-WVC7-CRWC? bumpalo (rust) versions >= 1.1.0, < 3.11.1 is affected.
- Is there a fix for GHSA-F85W-WVC7-CRWC? Yes. GHSA-F85W-WVC7-CRWC is fixed in 3.11.1. Upgrade to this version or later.
- Is GHSA-F85W-WVC7-CRWC exploitable, and should I be worried? Whether GHSA-F85W-WVC7-CRWC 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-F85W-WVC7-CRWC 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-F85W-WVC7-CRWC? Upgrade
bumpaloto 3.11.1 or later.