CVE-2026-59726: CVE-2026-59726: Ruflo is an agent meta-harness for Claude Code and Codex. Prior to 3.16.3, ruflo's default…
Unknown · Ruflo · NVD published 2026-07-09 · posted 2026-11-12 · last modified 2026-10-25
CVE-2026-59726 at a glance
CVE-2026-59726 is a critical-severity OS Command Injection vulnerability in Ruflo, with a CVSS 3.1 base score of 10. NVD published it on 2026-07-09 and classifies the weakness as CWE-78, CWE-306 and CWE-942. Public exploit code: 1 Exploit-DB entry, with the earliest exploit evidence dated 2026-11-11. FIRST EPSS puts the probability of exploitation activity in the next 30 days at 6.24% (percentile 93.6, scored 2026-11-14). NVD does not list a fixed version, so the vendor advisory is the reference for the fix. CVERadar maps 3 MITRE ATT&CK techniques across Initial Access, Execution, Stealth, Persistence and Privilege Escalation, inferred from the CWE and the description. Its CVERadar threat level is 59/100.
What it is
Ruflo is an agent meta-harness for Claude Code and Codex. Prior to 3.16.3, ruflo's default docker-compose deployment exposed the MCP bridge POST /mcp and POST /mcp/:group endpoints without authentication, allowing an unauthenticated network attacker to invoke tools/call to terminal_execute, obtain a shell in the bridge container, read provider API keys, and poison AgentDB learning-store patterns. This issue is fixed in version 3.16.3.
| Weakness | CWE-78 definition, CWE-306 definition, CWE-942 definition |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (source: GitHub) |
| ATT&CK tactics | Initial Access → Persistence → Privilege Escalation → Stealth → Execution |
CVERadar report: CVE-2026-59726: public exploit for this flaw, what we know
Exploitation evidence
First exploit evidence seen: 2026-11-11 (earliest date across the sources below).
Exploited in the wild
No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).
Public exploit code
Exploit-DB
- Exploit-DB EDB-52705: Ruflo MCP Bridge 3.16.2 - Remote Code Execution (2026-11-11)
GitHub proof-of-concept repositories below quality bar
1 public repositories from 1 accounts, first seen 2026-07-30.
Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.
Sources: Exploit-DB (OffSec) · nomi-sec/PoC-in-GitHub.
Defend the Chain
The attack chain for CVE-2026-59726 laid across the MITRE ATT&CK Enterprise tactics. Solid cards come from the MITRE CTID KEV mappings; dashed cards are inferred by CVERadar from the CWE or description. Correct defences are real ATT&CK mitigations for that technique.
Pick a red technique card on the board, then choose the defence that stops it.
Defend against T1190 Exploit Public-Facing Application Inferred
Inferred from CWE CWE-78
Patches, mitigations and detection
Fixed versions
NVD does not list a fixed version for this CVE. Use the vendor advisory below.
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
No vendor-tagged reference yet; see the full reference list.
MITRE ATT&CK mitigations for this chain
- M1048 Application Isolation and Sandboxing (for T1190) : Application isolation will limit what other processes and system features the exploited target can access.
- M1037 Filter Network Traffic (for T1190) : Restrict outbound network traffic from public-facing servers to prevent unauthorized connections from initiating communications with attacker-controlled infrastructure. While this may not prevent the initial exploitation, it limits the attacker's ability to verify and control the compromised server post-exploit, reduci
- M1030 Network Segmentation (for T1190) : Segment externally facing servers and services from the rest of the network with a DMZ or on separate hosting infrastructure.
- M1016 Vulnerability Scanning (for T1190) : Regularly scan externally facing systems for vulnerabilities and establish procedures to rapidly patch systems when critical vulnerabilities are discovered through scanning and through public disclosure.
- M1026 Privileged Account Management (for T1190, T1078, T1059) : Use least privilege for service accounts will limit what permissions the exploited process gets on the rest of the system.
- M1050 Exploit Protection (for T1190) : Web Application Firewalls may be used to limit exposure of applications to prevent exploit traffic from reaching the application.
- M1035 Limit Access to Resource Over Network (for T1190) : Ensure that all publicly exposed services are actually intended to be so, and restrict access to any that should only be available internally.
- M1051 Update Software (for T1190) : Update software regularly by employing patch management for externally exposed applications.
- M1027 Password Policies (for T1078) : Applications and appliances that utilize default username and password should be changed immediately after the installation, and before deployment to a production environment. When possible, applications that use SSH keys should be updated periodically and properly secured. Policies should minimize (if not eliminate)
- M1018 User Account Management (for T1078) : Regularly audit user accounts for activity and deactivate or remove any that are no longer needed.
Detection Generic guidance
- Initial Access: Alert on unusual requests to the affected service (odd paths, oversized payloads, exploit strings) in WAF, reverse-proxy and application logs.
- Persistence: Look for new files in web roots, new scheduled tasks/services, and new accounts created after the exposure window.
- Privilege Escalation: Alert on processes gaining SYSTEM/root unexpectedly, and on exploitation crashes of privileged services.
- Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.
Sources
- NVD: CVE-2026-59726
- CVE.org record for CVE-2026-59726
- FIRST EPSS score for CVE-2026-59726 (2026-11-14)
- GitHub fix commit (github.com) github.com/ruvnet/ruflo/commit/d00a0a40cd8bdbca877ac7f675f416bdc69accd1
- GitHub pull request (github.com) github.com/ruvnet/ruflo/pull/2521
- GitHub reference (github.com) github.com/ruvnet/ruflo/releases/tag/v3.16.3
- GitHub security advisory (github.com) github.com/ruvnet/ruflo/security/advisories/GHSA-c4hm-4h84-2cf3