GHSA-7vm6-qwh5-9x44 is a medium-severity (CVSS 4.3) CWE-755 vulnerability in loona-hpack. A fix is available for loona-hpack — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-7vm6-qwh5-9x44.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
loona-hpackReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Summary
loona-hpack suffers from the same vulnerability as the original hpack as documented in https://github.com/mlalic/hpack-rs/issues/11
Details
The original includes a very nice description of the problem, as well as an easy-enough fix for it.
PoC
The original example pretty much still applies:
use loona_hpack::Decoder;
pub fn main() {
let input = &[0x3f];
let mut decoder = Decoder::new();
let _ = decoder.decode(input);
}
Impact
From the original:
All users who try to decode untrusted input using the Decoder are vulnerable to this exploit. A patched version of the crate is available on [crates.io](https://crates.io/crates/hpack-patched) under the name hpack-patched. See [Cargo's documentation on overriding dependencies](https://doc.rust-lang.org/cargo/reference/overriding-dependencies.html) for more information.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | loona-hpack | all versions | 0.4.3cargo update -p loona-hpack --precise 0.4.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for loona-hpack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update loona-hpack to 0.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7vm6-qwh5-9x44 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is GHSA-7vm6-qwh5-9x44 in your dependencies?
Find it across crates.io, including transitive dependencies.