Improper Restriction of Excessive Authentication Attempts in py-bcryptGHSA-r838-q6jp-58xx
HIGHGHSA-r838-q6jp-58xx is a high-severity (CVSS 7.5) CWE-307 vulnerability in py-bcrypt. A fix is available for py-bcrypt — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-r838-q6jp-58xx by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
py-bcryptReal-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 py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | py-bcrypt | all versions | 0.3pip install --upgrade 'py-bcrypt==0.3' |
Affected Products
fedorafedoraprojectpy-bcryptpythonDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for py-bcrypt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update py-bcrypt to 0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-r838-q6jp-58xx 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 GHSA-r838-q6jp-58xx in your dependencies?
Find it across PyPI, including transitive dependencies.