CVE-2026-118657
Tenable Plugin
Checking the public Tenable catalog…
AI Threat Summary
CVE-2026-118657 is a moderate vulnerability with a CVSS score of 5.9 affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
Description
Echo is a Go web framework. Prior to 4.16.0 and 5.4.0, Context.Scheme unconditionally trusts forwarded scheme headers from any client. A client that reaches Echo directly over plaintext HTTP can claim an HTTPS scheme and bypass HTTPSRedirect because the request is treated as already secure. Separately, behind a TLS-terminating proxy that passes an attacker-controlled header, a claimed HTTP scheme can suppress the Strict-Transport-Security header even though the browser receives the response over HTTPS. The practical risk is reduced when a trusted proxy overwrites the headers and direct backend access is prevented, but the framework previously had no trusted-source configuration for this decision. This issue is fixed in 4.16.0 and 5.4.0.
Attack Chain
Attacker identifies vulnerable service instances using Shodan, Censys, or active scanning
Attacker crafts malicious payload exploiting CVE-2026-118657 to achieve remote code execution
Attacker executes arbitrary OS commands or shellcode in the context of the vulnerable process
Attacker installs backdoor, cron job, or web shell for persistent access
Attacker uses compromised host as pivot point to access internal network resources
MITRE ATT&CK Techniques
Attacker exploits the vulnerability in an internet-facing service to gain initial access
Post-exploitation shell commands executed through the vulnerability
Attacker downloads malware or tools after gaining code execution
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params | |
| registry_key | HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\backdoor |
Persistence mechanism after successful RCE |
Remediation
Quick Facts
| CVE ID | CVE-2026-118657 |
| CVSS Score | 5.9 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N |
| Published | 2026-10-28 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |