# CVE-2026-51886: Langflow: Title Authenticated Remote Code Execution in validate_code via Malicious Decorators Description

> An authenticated attacker can execute arbitrary Python code on the server by submitting malicious input to the code validation endpoint.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Oct 2026
- **Updated:** 5 Oct 2026
- **Also known as:** GHSA-w584-2h2r-2hvf, PYSEC-2026-4236

## What is CVE-2026-51886?

CVE-2026-51886 is a critical code injection vulnerability in n/a, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

langflow-ai langflow v1.9.3 is affected by: Code Injection. The impact is: execute arbitrary code (remote). The component is: src/backend/base/langflow/api/v1/validate.py:validate-post_validate_code-a-real-authenticated-http-post-to-api-v1. The attack vector is: Attack surface: HTTP or browser-backed service path. A public-facing route accepts raw Python source and forwards it into a server-side compile/exec validation path without any visible entitlement guard. ¶¶ A weakness has been identified in langflow-ai langflow up to 1.9.3. langflow contains a code injection vulnerability in validate-post_validate_code-a-real-authenticated-http-post-to-api-v1 (src/backend/base/langflow/api/v1/validate.py:13). An authenticated attacker can execute arbitrary Python code on the server by submitting malicious code to the /api/v1/validate/code endpoint, which directly executes user-supplied code without sandboxing or security controls.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-51886?

3 open source packages ship an affected version, including langflow.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `langflow` | PyPI | From 1.7.2 | 1.10.1 |
| `langflow` | PyPI | From 1.7.2 | 1.10.1 |
| `langflow` | PyPI | From 1.7.2 | 1.10.1 |

## How do I fix CVE-2026-51886?

Upgrade langflow to 1.10.1 or later.

## Is CVE-2026-51886 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-51886 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-51886 and fix it if it is affected.

What it is: CVE-2026-51886 is a critical code injection vulnerability in n/a, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-51886 exists.

Affected packages and fixed versions:
- langflow (PyPI): affected from 1.7.2; fixed in 1.10.1
- langflow (PyPI): affected from 1.7.2; fixed in 1.10.1
- langflow (PyPI): affected from 1.7.2; fixed in 1.10.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-51886/ (Markdown: https://insights.sbomify.com/CVE-2026-51886/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-51886
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-51886
- OSV: https://osv.dev/vulnerability/CVE-2026-51886

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-51886/
Summaries are generated and may contain mistakes; the official description above is the record.