GHSA-gw7g-qr8w-3448 is a high-severity (CVSS 7.5) CWE-674 vulnerability in remarshal. A fix is available for remarshal — see the affected versions and patch details below.
Remarshal expands YAML alias nodes unlimitedly, hence Remarshal is vulnerable to Billion Laughs Attack
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-gw7g-qr8w-3448.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-gw7g-qr8w-3448 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 379,842 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
remarshalReal-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
Remarshal prior to v0.17.1 expands YAML alias nodes unlimitedly, hence Remarshal is vulnerable to Billion Laughs Attack. Processing untrusted YAML files may cause a denial-of-service (DoS) condition.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | remarshal | all versions | 0.17.1pip install --upgrade 'remarshal==0.17.1' |
Affected Products
remarshalremarshal_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for remarshal, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update remarshal to 0.17.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gw7g-qr8w-3448 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-gw7g-qr8w-3448 in your dependencies?
Find it across PyPI, including transitive dependencies.