CVE-2026-118688
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AI Threat Summary
CVE-2026-118688 is a high-severity vulnerability with a CVSS score of 7.9 affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
Description
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
Attack Chain
Attacker identifies vulnerable service instances using Shodan, Censys, or active scanning
Attacker crafts malicious payload exploiting CVE-2026-118688 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-2026-118688 |
| CVSS Score | 7.9 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L |
| Published | 2026-10-28 |
| Exploited | No |
| CISA KEV | No |
| PoC | Available |