CVE-2022-3212 is a high-severity (CVSS 7.5) CWE-770 vulnerability in axum-core. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for axum-core — see the affected versions and patch details below.
axum-core has no default limit put on request bodies
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
axum-core🦀axum-coreReal-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
<bytes::Bytes as axum_core::extract::FromRequest>::from_request would not, by default, set a limit for the size of the request body. That meant if a malicious peer would send a very large (or infinite) body your server might run out of memory and crash.
This also applies to these extractors which used Bytes::from_request internally:
axum::extract::Formaxum::extract::JsonString
The fix is also in axum-core 0.3.0.rc.2 but 0.3.0.rc.1 is vulnerable.
Because axum depends on axum-core it is vulnerable as well. The vulnerable versions of axum are <= 0.5.15 and 0.6.0.rc.1. axum >= 0.5.16 and >= 0.6.0.rc.2 does have the fix and are not vulnerable.
The patched versions will set a 2 MB limit by default.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | axum-core | all versions | 0.2.8cargo update -p axum-core --precise 0.2.8 |
| 🦀crates.io | axum-core | ≥ 0.3.0-rc.1&&< 0.3.0-rc.2 | 0.3.0-rc.2cargo update -p axum-core --precise 0.3.0-rc.2 |
Affected Products
axum-coreaxum-core_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for axum-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update axum-core to 0.2.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-3212 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2022-3212 in your dependencies?
Find it across crates.io, including transitive dependencies.