How severe is CVE-2026-33017?

No CVSS score has been assigned to CVE-2026-33017 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-33017?

CVE-2026-33017 affects the following packages: langflow (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-33017?

Update langflow to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33017 is resolved across your whole dependency graph.

How do I detect CVE-2026-33017 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langflow. 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.

How do I mitigate CVE-2026-33017 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2026-33017?

O3 pinpoints whether CVE-2026-33017 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-33017 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2026-33017, including 1 documented proof-of-concept exploit on Exploit-DB. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2026-33017?

CVE-2026-33017 has an EPSS (Exploit Prediction Scoring System) score of 99.8%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2026-33017 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2026-33017 (Langflow Code Injection Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-03-25. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-04-08. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2026-33017?

CVE-2026-33017 is classified as Code Injection (CWE-94), CWE-95 (CWE-95), Missing Authentication (CWE-306). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for CVE-2026-33017?

A Nuclei detection template exists for CVE-2026-33017, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2026-33017 published, and has it been updated?

CVE-2026-33017 was published on March 20, 2026 and was last updated on July 15, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-33017: langflow Remote Code Execution

EPSS Exploitation Probability

via FIRST.org ↗

99.8%probability of exploitation in next 30 days

Very High Risk100th percentile+1.34%

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

1 pkg affected

🐍langflow

Real-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

Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring authentication. When the optional data parameter is supplied, the endpoint uses attacker-controlled flow data (containing arbitrary Python code in node definitions) instead of the stored flow data from the database. This code is passed to exec() with zero sandboxing, resulting in unauthenticated remote code execution. This is distinct from CVE-2025-3248, which fixed /api/v1/validate/code by adding authentication. The build_public_tmp endpoint is designed to be unauthenticated (for public flows) but incorrectly accepts attacker-supplied flow data containing arbitrary executable code. This issue has been fixed in version 1.9.0.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`langflow`	all versions	1.9.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langflow. 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 langflow to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33017 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-2026-33017 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-2026-33017. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring authentication. When the optional data parameter is supplied, the endpoint uses attacker-controlled flow data (containing arbitrary Python code in node definitions) instead of the stored flow data from the database. This code is passed to exec() with zero sandboxing, resulting in unauthenticated remote code execution. This is distinct from CVE-2025-3248, which fixed /api/v1/validate/co

O3 Security · Impact-Aware SCA

Is CVE-2026-33017 in your dependencies?

O3 detects CVE-2026-33017 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2026-33017