Unlimited consumption of resources in @fastify/multipartGHSA-27c6-mcxv-x3fh
HIGHFix: fastify/fastify-multipart#567GHSA-27c6-mcxv-x3fh is a high-severity (CVSS 7.5) CWE-770 vulnerability in @fastify/multipart. A fix is available for @fastify/multipart — 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.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-27c6-mcxv-x3fh.
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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@fastify/multipartnpmDescription
Impact
The saveRequestFiles function does not delete the uploaded temporary files when user cancels the request.
Patches
Fixed in version 8.3.1 and 9.0.3
Workarounds
Do not use saveRequestFiles.
References
This was identified in https://github.com/fastify/fastify-multipart/issues/546 and fixed in https://github.com/fastify/fastify-multipart/pull/567.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @fastify/multipart | all versions | 8.3.1npm install @fastify/multipart@8.3.1 |
| 📦npm | @fastify/multipart | ≥ 9.0.0&&< 9.0.3 | 9.0.3npm install @fastify/multipart@9.0.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @fastify/multipart, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @fastify/multipart to 8.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-27c6-mcxv-x3fh 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 GHSA-27c6-mcxv-x3fh in your dependencies?
Find it across npm, including transitive dependencies.