CVE-2026-30650: Vivotek FD8136 Firmware RCE Vulnerability

CVE-2026-30650 Overview

CVE-2026-30650 is a post-authentication remote buffer overflow vulnerability in Vivotek FD8136 network cameras running firmware version FD8136-VVTK-0300a. The flaw resides in the /cgi-bin/admin/eventtask.cgi endpoint of the device administrative interface. An authenticated attacker can send a crafted HTTP request that overflows a stack buffer and executes arbitrary code as root on the camera. The weakness is classified as a classic buffer copy without size checking [CWE-120].

Critical Impact
Authenticated attackers gain remote root-level code execution on affected Vivotek FD8136 cameras, enabling full device takeover, video feed manipulation, and pivoting into adjacent network segments.

Affected Products

Vivotek FD8136 IP camera (hardware)
Vivotek FD8136 firmware version FD8136-VVTK-0300a
Deployments exposing the /cgi-bin/admin/eventtask.cgi administrative endpoint

Discovery Timeline

2026-06-02 - CVE-2026-30650 published to NVD
2026-06-03 - Last updated in NVD database

Technical Details for CVE-2026-30650

Vulnerability Analysis

The vulnerability exists in the eventtask.cgi binary that handles administrative event-task configuration requests on Vivotek FD8136 cameras. The CGI process runs with root privileges and accepts HTTP parameters from authenticated administrative users. One or more of these parameters are copied into a fixed-size stack buffer without validating the length of the input. When the supplied parameter exceeds the destination buffer, adjacent stack data including the saved return address is overwritten.

Because the firmware does not enforce robust exploit mitigations on this binary, an attacker can redirect control flow into attacker-supplied data and execute arbitrary instructions. The result is full code execution within the camera operating system with the highest privilege level. Technical research and analysis are documented in the GitHub CVE-2026-30650 Research repository.

Root Cause

The root cause is an unchecked memory copy operation in the request-handling logic of /cgi-bin/admin/eventtask.cgi. User-controlled HTTP parameter data is written into a stack-allocated buffer of insufficient size, producing a classic stack-based buffer overflow [CWE-120]. The CGI process inherits root privileges from the embedded web server, which makes any control-flow hijack equivalent to full device compromise.

Attack Vector

Exploitation requires network reachability to the camera administrative interface and valid administrator credentials. The attacker authenticates to the web management interface, then issues a crafted HTTP request to /cgi-bin/admin/eventtask.cgi containing an oversized parameter value. The malformed parameter overflows the target buffer and overwrites saved control-flow state, allowing execution of attacker-controlled shellcode or a return-oriented programming payload. The EPSS score for this CVE is 0.386% as of 2026-06-04, and no public weaponized exploit or CISA KEV listing has been reported.

No verified proof-of-concept code is published in the enriched data. See the GitHub CVE-2026-30650 Research repository for technical reverse-engineering details.

Detection Methods for CVE-2026-30650

Indicators of Compromise

HTTP POST or GET requests to /cgi-bin/admin/eventtask.cgi containing unusually long parameter values or binary shellcode-like byte sequences.
Unexpected outbound connections initiated by the camera to attacker-controlled hosts after administrative requests.
Unscheduled reboots, crashes, or process restarts of the camera web server following requests to the event-task endpoint.
New or modified scheduled tasks, cron entries, or persistence artifacts on the camera filesystem.

Detection Strategies

Inspect web server and reverse-proxy logs for requests targeting /cgi-bin/admin/eventtask.cgi where parameter lengths exceed typical administrative input sizes.
Deploy network IDS signatures that flag oversized parameter strings or non-printable bytes inside POST bodies addressed to Vivotek camera management endpoints.
Monitor for authentication anomalies against camera administrative accounts, including credential stuffing or unusual source IPs preceding event-task requests.
Correlate camera-originated outbound traffic with prior administrative HTTP sessions to detect post-exploitation callbacks.

Monitoring Recommendations

Centralize camera and network device logs in a SIEM and alert on access to /cgi-bin/admin/ endpoints from non-administrative source ranges.
Baseline normal camera outbound traffic and alert on deviations such as new destinations, unusual ports, or sustained data egress.
Track firmware versions across the IP camera fleet and alert when devices remain on firmware FD8136-VVTK-0300a.

How to Mitigate CVE-2026-30650

Immediate Actions Required

Remove direct internet exposure of Vivotek FD8136 administrative interfaces and restrict access to a dedicated management VLAN.
Rotate all administrator credentials on affected cameras and disable any shared or default accounts.
Place cameras behind a reverse proxy or firewall that enforces request size limits and authentication controls on /cgi-bin/admin/ paths.
Audit recent access logs for requests to /cgi-bin/admin/eventtask.cgi and investigate any suspicious sessions.

Patch Information

No vendor advisory or firmware patch URL is referenced in the enriched data at publication time. Administrators should consult the Vivotek Security Resource for vendor updates and apply any released firmware that supersedes FD8136-VVTK-0300a as soon as it becomes available.

Workarounds

Segment IP cameras onto an isolated network with no route to corporate systems or the public internet.
Enforce strong, unique administrator passwords and enable account lockout to reduce the value of stolen credentials.
Restrict HTTP access to camera management endpoints using firewall ACLs that allow only trusted operator workstations.
Disable remote administrative access entirely on cameras that are managed exclusively from on-site networks.

bash

# Example firewall ACL restricting access to Vivotek camera admin endpoints
# Replace 10.10.50.0/24 with your authorized management subnet
# Replace 192.0.2.10 with the camera IP
iptables -A FORWARD -s 10.10.50.0/24 -d 192.0.2.10 -p tcp --dport 80 -j ACCEPT
iptables -A FORWARD -d 192.0.2.10 -p tcp --dport 80 -j DROP