Attackers Exploit Critical Langflow and Rails Flaws in Credential
VulnCheck reports active exploitation of critical Langflow CVE-2026-0768 and Rails CVE-2026-66066 for credential harvesting, with detections rising to 360.
VulnCheck observed active exploitation of CVE-2026-0768 (CVSS 9.8) in Langflow and CVE-2026-66066 'KindaRails2Shell' (CVSS 9.5) in Ruby on Rails, with detections rising from 50 on August 30, 2026 to 360 by September 1. The Rails flaw allows unauthenticated arbitrary file reads, leaking secret_key_base, Rails master key, database passwords, cloud credentials and API tokens, ultimately enabling RCE; the patch still leaves the variation-key Marshal deserialization RCE gadget functional. Observed chains include a Python credential harvester with SimpleHelp remote access via CVE-2026-5027, and weaponization of CVE-2025-3248 to enlist hosts into an XMR mining botnet after disabling auditd. More than 7,100 exposed vulnerable Ruby on Rails instances and over 15,000 successful exploitation attempts across three Langflow flaws were recorded.
- Detections rose from 50 on August 30 to 360 by Monday, mostly hitting VulnCheck canaries in the UK.
- Attackers query environment variables (OPENAI_API*, AWS keys) and read Langflow secret keys for credential harvesting.
- Patched Rails 8.1.3.1 blocks the libvips file read but the variation-key Marshal deserialization RCE gadget still executes.
- Over 15,000 successful exploitation attempts recorded across CVE-2026-0769, CVE-2025-3248 and CVE-2026-5027 since 2025.
- Observed chains include SimpleHelp remote access, XMR crypto-mining botnet enlistment and auditd disabling.
- ATT&CK
- T1190 Exploit Public-Facing ApplicationT1059.006 PythonT1552.001 Credentials In FilesT1219 Remote Access SoftwareT1496 Resource Hijacking
- Products
- LangflowSimpleHelp
- Threat actors
- Unknown
- Malware
- Python credential harvester
- Organizations
- VulnCheck
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| CVE-2025-3248 | Unauthenticated RCE in Langflow /api/v1/validate/code | 9.8 | 100% | KEVRansomwarePoC ×4 | KEV |
CVE-2026-0769+1 related CVE | Unauthenticated Eval Injection RCE in Langflow (eval_custom_component_code) | 9.8 | 41% | PoC | |
| CVE-2026-5027 | Authenticated Path Traversal Arbitrary File Write in Langflow Files API | 8.8 | 36% | ||
| CVE-2026-66066 | Unauthenticated Arbitrary File Read in Ruby on Rails Active Storage | 9.5 | 30% | PoC |
From the original article
2 min read at thehackernews.com
Ravie Lakshmanan Sep 01, 2026 Vulnerability / Artificial Intelligence Threat actors are exploiting two critical flaws impacting Langflow and Ruby on Rails, according to new findings from VulnCheck. CVE-2026-0768 (CVSS score: 9. 8) - A lack of proper validation of a user-supplied input vulnerability that could be exploited to execute arbitrary Python code in the context of the root user.
By @TheHackersNews · thehackernews.com
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