copyparty allows Regex Denial of Service (ReDoS) in the upload listingGHSA-5662-2rj7-f2v6
HIGHFix: 9001/copyparty@09910baGHSA-5662-2rj7-f2v6 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in copyparty. A fix is available for copyparty — 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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-5662-2rj7-f2v6.
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
copypartyReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The filter parameter for the "Recent uploads" page allows arbitrary Regexes. If this feature is enabled (which is the default), an attacker can craft a filter which deadlocks the server.
PoC
https://127.0.0.1:3923/?ru&filter=(.+)+x
Impact
The server becomes fully inaccessible for a long time.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | copyparty | all versions | 1.18.9pip install --upgrade 'copyparty==1.18.9' |
Affected Products
copyparty9001Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for copyparty, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update copyparty to 1.18.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5662-2rj7-f2v6 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-5662-2rj7-f2v6 in your dependencies?
Find it across PyPI, including transitive dependencies.