pywasm3 contains a global buffer overflow which leads to segmentation faultGHSA-hh39-vjv8-j337
CRITICALGHSA-hh39-vjv8-j337 is a critical-severity (CVSS 9.8) CWE-120 vulnerability in pywasm3. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
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.
- 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-hh39-vjv8-j337.
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
pywasm3Real-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
wasm3 v0.5.0 was discovered to contain a global buffer overflow which leads to segmentation fault via the function "PreserveRegisterIfOccupied" in wasm3/source/m3_compile.c.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pywasm3 | all versions | No fix |
Affected Products
wasm3wasm3_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pywasm3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of pywasm3 for GHSA-hh39-vjv8-j337. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Frequently Asked Questions
Is GHSA-hh39-vjv8-j337 in your dependencies?
Find it across PyPI, including transitive dependencies.