CVE-2016-1494 is a medium-severity (CVSS 5.3) Improper Input Validation vulnerability in rsa. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for rsa — see the affected versions and patch details below.
Python RSA allows attackers to spoof signatures
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
rsaReal-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
The verify function in the RSA package for Python (Python-RSA) before 3.3 allows attackers to spoof signatures with a small public exponent via crafted signature padding, aka a BERserk attack.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | rsa | all versions | 3.3pip install --upgrade 'rsa==3.3' |
Affected Products
fedorafedoraprojectleapopensuseopensuseopensusersapythonResearch 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 rsa, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rsa to 3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-1494 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2016-1494 in your dependencies?
Find it across PyPI, including transitive dependencies.