EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
python-apt🐍python-apt🐍python-apt🐍python-apt🐍python-aptReal-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
Python-apt doesn't check if hashes are signed in Version.fetch_binary() and Version.fetch_source() of apt/package.py or in _fetch_archives() of apt/cache.py in version 1.9.3ubuntu2 and earlier. This allows downloads from unsigned repositories which shouldn't be allowed and has been fixed in verisions 1.9.5, 1.9.0ubuntu1.2, 1.6.5ubuntu0.1, 1.1.0~beta1ubuntu0.16.04.7, 0.9.3.5ubuntu3+esm2, and 0.8.3ubuntu7.5.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | python-apt | all versions | 0.8.3ubuntu7.5 |
| 🐍PyPI | python-apt | ≥ 0.9.0&&< 0.9.3.5ubuntu3 | 0.9.3.5ubuntu3 |
| 🐍PyPI | python-apt | ≥ 1.2.0&&< 1.6.5ubuntu0.1 | 1.6.5ubuntu0.1 |
| 🐍PyPI | python-apt | ≥ 1.7.0&&< 1.9.0ubuntu1.2 | 1.9.0ubuntu1.2 |
| 🐍PyPI | python-apt | ≥ 1.9.1&&< 1.9.5 | 1.9.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for python-apt. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update python-apt to 0.8.3ubuntu7.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-15796 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.
How O3 protects you
O3 pinpoints whether CVE-2019-15796 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2019-15796. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2019-15796 in your dependencies?
O3 detects CVE-2019-15796 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.