CVE-2026-33752
HIGHCVE-2026-33752 is a high-severity (CVSS 8.6) Server-Side Request Forgery (SSRF) vulnerability in curl-cffi. O3 Security confirms whether CVE-2026-33752 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Redirect-based SSRF leading to internal network access in curl_cffi (with TLS impersonation bypass)
Blast Radius
curl-cffiReal-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
curl_cffi is the a Python binding for curl. Prior to 0.15.0, curl_cffi does not restrict requests to internal IP ranges, and follows redirects automatically via the underlying libcurl. Because of this, an attacker-controlled URL can redirect requests to internal services such as cloud metadata endpoints. In addition, curl_cffi’s TLS impersonation feature can make these requests appear as legitimate browser traffic, which may bypass certain network controls. This vulnerability is fixed in 0.15.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | curl-cffi | all versions | 0.15.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for curl-cffi. 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 curl-cffi to 0.15.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33752 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-2026-33752 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-2026-33752. 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-2026-33752 in your dependencies?
O3 detects CVE-2026-33752 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.