CVE-2026-89009: Absolute Path Traversal in WAVLINK Technology WN535M1
WAVLINK WN535M1 and WN535M3 routers running firmware prior to M35M1_V250922 contain an unauthenticated arbitrary file write vulnerability that allows remote attackers to overwrite any file on the device by sending a crafted payload to the sync_server daemon on TCP port 13136. The daemon, which runs as root and requires no authentication, accepts a 100-byte filename field in its protocol header without path canonicalization, allowing attackers to supply an absolute path and write arbitrary content to overwrite startup scripts or credential stores to achieve persistent system compromise.
AI Analysis
Technical Summary
CVE-2026-89009 describes an unauthenticated absolute path traversal vulnerability in WAVLINK WN535M1 and WN535M3 routers running firmware before M35M1_V250922. The sync_server daemon listens on TCP port 13136 and runs with root privileges. It accepts a 100-byte filename field in its protocol header without validating or canonicalizing the path, enabling remote attackers to write arbitrary files by specifying absolute paths. This vulnerability allows overwriting of critical system files, potentially leading to persistent compromise of the device.
Potential Impact
An attacker can remotely overwrite any file on the affected device without authentication by exploiting the path traversal flaw in the sync_server daemon. Because the daemon runs as root, this can result in persistent system compromise by modifying startup scripts or credential stores. The vulnerability has a high severity with a CVSS 4.0 score of 8.8, indicating significant risk if exploited.
Mitigation Recommendations
No explicit patch or remediation information is provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restricting network access to TCP port 13136 and disabling the sync_server daemon if possible may reduce exposure.
CVE-2026-89009: Absolute Path Traversal in WAVLINK Technology WN535M1
Description
WAVLINK WN535M1 and WN535M3 routers running firmware prior to M35M1_V250922 contain an unauthenticated arbitrary file write vulnerability that allows remote attackers to overwrite any file on the device by sending a crafted payload to the sync_server daemon on TCP port 13136. The daemon, which runs as root and requires no authentication, accepts a 100-byte filename field in its protocol header without path canonicalization, allowing attackers to supply an absolute path and write arbitrary content to overwrite startup scripts or credential stores to achieve persistent system compromise.
CVSS v4.0
Score 8.8high
Affected software
WAVLINK Technology
WN535M1
WAVLINK Technology
WN535M3
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-89009 describes an unauthenticated absolute path traversal vulnerability in WAVLINK WN535M1 and WN535M3 routers running firmware before M35M1_V250922. The sync_server daemon listens on TCP port 13136 and runs with root privileges. It accepts a 100-byte filename field in its protocol header without validating or canonicalizing the path, enabling remote attackers to write arbitrary files by specifying absolute paths. This vulnerability allows overwriting of critical system files, potentially leading to persistent compromise of the device.
Potential Impact
An attacker can remotely overwrite any file on the affected device without authentication by exploiting the path traversal flaw in the sync_server daemon. Because the daemon runs as root, this can result in persistent system compromise by modifying startup scripts or credential stores. The vulnerability has a high severity with a CVSS 4.0 score of 8.8, indicating significant risk if exploited.
Mitigation Recommendations
No explicit patch or remediation information is provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restricting network access to TCP port 13136 and disabling the sync_server daemon if possible may reduce exposure.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-10T16:23:54.470Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6aa4180791cc7f38484fb5c1
Added to database: 09/11/2026, 15:02:31 UTC
Last enriched: 09/11/2026, 15:18:02 UTC
Last updated: 09/11/2026, 19:42:42 UTC
Views: 5
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