CVE-2026-58501 is a medium-severity (CVSS 5.9) Server-Side Request Forgery (SSRF) vulnerability in zeep. A fix is available for zeep — see the affected versions and patch details below.
Zeep SSRF because Settings.forbid_external is not enforced
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-58501.
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.
How urgent is this, really
CVE-2026-58501 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 374,847 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
zeepReal-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
Zeep is a Python SOAP client. From 4.0.0 before 4.3.3, Settings.forbid_external is defined but not enforced when parsing WSDL or XSD documents, allowing transitive xsd:import, xsd:include, wsdl:import, and lxml entity or DTD references to fetch attacker-chosen HTTP or HTTPS URLs. This issue is fixed in version 4.3.3.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | zeep | ≥ 4.0.0&&< 4.3.3 | 4.3.3pip install --upgrade 'zeep==4.3.3' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zeep, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update zeep to 4.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-58501 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-58501 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-58501. 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-2026-58501 in your dependencies?
O3 Security finds CVE-2026-58501 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.