CVE-2026-44353
MEDIUMCVE-2026-44353 is a medium-severity (CVSS 6.5) vulnerability in streamlink. O3 Security confirms whether CVE-2026-44353 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Streamlink: Arbitrary local file read via file:// URI in HLS and DASH
Real-World Exposure
streamlinkReal-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
Streamlink is a CLI utility which pipes video streams from various services into a video player. Prior to 8.4.0, Streamlink's HLS and DASH parsers do not validate the URI scheme of segment entries and other resources. A remote .m3u8 HLS playlist or .mpd DASH manifest can list file:///path/to/file as a segment, and streamlink will read that local file and write its contents to the output stream. This vulnerability is fixed in 8.4.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | streamlink | all versions | 8.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for streamlink. 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 streamlink to 8.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44353 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-2026-44353 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-2026-44353. 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-2026-44353 in your dependencies?
O3 detects CVE-2026-44353 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.