CVE-2026-66747
ENDLESSDOORS: Zbtlink Router rctl/kworker Phone-Home Root Implant
Description
Zbtlink router firmware ships an embedded remote-control implant, ENDLESSDOORS, present in every published build across the product line. It is the open-source ycsunjane/rctl tool built in as an OpenWrt package (librctl.so), started at boot and run as root under the process name kworker to blend in with the kernel's [kworker/*] threads. It opens no listening port; it phones home over cleartext TCP to a hardcoded command-and-control server (command channel 7000, interactive-shell callback 7001) with no authentication and no transport encryption, re-attempting contact roughly every 35 seconds. Its command handler passes any received string to popen() as uid=0, and a reserved rctlbash command returns an interactive root shell. Because the channel is unauthenticated and cleartext, control is not limited to whoever planted it: any party that answers at the C2 address, occupies the network path (DNS or route hijack), or acquires the hardcoded fallback domain obtains unauthenticated remote code execution as root.
INFO
Published Date :
Aug. 5, 2026, 11:16 a.m.
Last Modified :
Aug. 5, 2026, 3:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-66747
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 3.1 | CRITICAL | MITRE-CVE | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update router firmware to the latest version.
- Disable remote management features.
- Monitor network traffic for suspicious connections.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-66747.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-66747 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-66747
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-66747 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-66747 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 05, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-66747', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-05T14:19:25.533200Z'} -
New CVE Received by [email protected]
Aug. 05, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:2.3:o:zbtlink:cpe2801_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'CPE2801 Firmware', 'versions': [{'status': 'affected', 'version': '22.10.09', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we1026-5g-wd_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE1026-5G-WD Firmware', 'versions': [{'status': 'affected', 'version': '21.04.07', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we1326_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE1326 Firmware', 'versions': [{'status': 'affected', 'version': '22.02.18_1', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we2007_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE2007 Firmware', 'versions': [{'status': 'affected', 'version': '23.08.12', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we2008-dsim_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE2008-DSIM Firmware', 'versions': [{'status': 'affected', 'version': '23.08.11', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we2416_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE2416 Firmware', 'versions': [{'status': 'affected', 'version': '21.03.22_1', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we3326_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE3326 Firmware', 'versions': [{'status': 'affected', 'version': '20.09.30', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we5927_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE5927 Firmware', 'versions': [{'status': 'affected', 'version': '22.08.10', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we5931_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE5931 Firmware', 'versions': [{'status': 'affected', 'version': '22.05.31', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we5931ac_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE5931AC Firmware', 'versions': [{'status': 'affected', 'version': '22.05.31', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:we826-t3-dsim_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WE826-T3-DSIM Firmware', 'versions': [{'status': 'affected', 'version': '21.12.21', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:wg108_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WG108 Firmware', 'versions': [{'status': 'affected', 'version': '21.08.06_1', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:wg209_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WG209 Firmware', 'versions': [{'status': 'affected', 'version': '21.07.28', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:wg259_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WG259 Firmware', 'versions': [{'status': 'affected', 'version': '21.03.23', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:wg1602_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WG1602 Firmware', 'versions': [{'status': 'affected', 'version': '23.10.11', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:wg1608-dsim_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WG1608-DSIM Firmware', 'versions': [{'status': 'affected', 'version': '23.03.16', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:wg2105_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WG2105 Firmware', 'versions': [{'status': 'affected', 'version': '22.05.30', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:wg2107_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WG2107 Firmware', 'versions': [{'status': 'affected', 'version': '22.09.08', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:wg3526_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'WG3526 Firmware', 'versions': [{'status': 'affected', 'version': '22.11.01', 'versionType': 'custom'}], 'platforms': ['MIPS', 'ARM'], 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:2.3:o:zbtlink:z8102ax_firmware:*:*:*:*:*:*:*:*'], 'vendor': 'Zbtlink', 'product': 'ZBT-Z8102AX-2SIM Firmware', 'versions': [{'status': 'affected', 'version': '7.6.7.2-25.0814_114432', 'versionType': 'custom'}], 'platforms': ['ARM'], 'defaultStatus': 'unaffected'}] Added Description Zbtlink router firmware ships an embedded remote-control implant, ENDLESSDOORS, present in every published build across the product line. It is the open-source ycsunjane/rctl tool built in as an OpenWrt package (librctl.so), started at boot and run as root under the process name kworker to blend in with the kernel's [kworker/*] threads. It opens no listening port; it phones home over cleartext TCP to a hardcoded command-and-control server (command channel 7000, interactive-shell callback 7001) with no authentication and no transport encryption, re-attempting contact roughly every 35 seconds. Its command handler passes any received string to popen() as uid=0, and a reserved rctlbash command returns an interactive root shell. Because the channel is unauthenticated and cleartext, control is not limited to whoever planted it: any party that answers at the C2 address, occupies the network path (DNS or route hijack), or acquires the hardcoded fallback domain obtains unauthenticated remote code execution as root. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-506 Added Reference https://github.com/ycsunjane/rctl Added Reference https://www.vulncheck.com/advisories/zbt-endlessdoors Added Reference https://www.vulncheck.com/blog/zbt-endlessdoors Added Reference https://www.zbtlink.com/pages/zbt-router-firmware-download