# CVE-2026-67426: Flyto2 Core: Unauthenticated flyto-verification /run: callback_url SSRF and internal runner-secret exfiltration

> Unauthenticated attackers can trigger SSRF and exfiltrate internal runner secrets via the verification service callback URL.

- **Severity:** Critical 9.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Jul 2026
- **Updated:** 29 Jul 2026
- **Also known as:** GHSA-jx74-cqjv-2c67, PYSEC-2026-3571

## What is CVE-2026-67426?

CVE-2026-67426 is a critical server-side request forgery vulnerability in flytohub flyto-core, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Flyto2 Core is an execution kernel for automation and AI-agent workflows. Prior to 2.26.7, the standalone flyto-verification service in src/core/verification_service.py exposes unauthenticated POST /run on 0.0.0.0:8344 and uses client-supplied callback_url for an outbound POST with X-Internal-Key: $FLYTO_RUNNER_SECRET while bypassing target_allowed, allowing unauthenticated SSRF and runner secret exfiltration. This issue is fixed in version 2.26.7.

Weakness: CWE-918 (Server-Side Request Forgery), CWE-522 (Insufficiently Protected Credentials), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-67426?

3 open source packages ship an affected version, including flyto-core.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `flyto-core` | PyPI | All versions | 2.26.7 |
| `flyto-core` | PyPI | From 2.26.6 | 2.26.7 |
| `flyto-core` | PyPI | From 2.26.6 | 2.26.7 |

## How do I fix CVE-2026-67426?

Upgrade flyto-core to 2.26.7 or later.

## Is CVE-2026-67426 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67426 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-67426 and fix it if it is affected.

What it is: CVE-2026-67426 is a critical server-side request forgery vulnerability in flytohub flyto-core, published on 29 Jul 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-2026-67426 exists.

Affected packages and fixed versions:
- flyto-core (PyPI): affected all versions; fixed in 2.26.7
- flyto-core (PyPI): affected from 2.26.6; fixed in 2.26.7
- flyto-core (PyPI): affected from 2.26.6; fixed in 2.26.7

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-2026-67426/ (Markdown: https://insights.sbomify.com/CVE-2026-67426/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-67426
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-67426
- OSV: https://osv.dev/vulnerability/CVE-2026-67426

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-67426/
Summaries are generated and may contain mistakes; the official description above is the record.