CVE-2026-89009

Summary

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.

Affected Software

VendorProductVersion RangeStatus
WAVLINK TechnologyWN535M1M35M1_V210223affected
WAVLINK TechnologyWN535M1M35M1_V250922unaffected
WAVLINK TechnologyWN535M3M35M1_V210223affected
WAVLINK TechnologyWN535M3M35M1_V250922unaffected

Weaknesses

  • CWE-36: Absolute Path Traversal

References