{"id":"CVE-2026-89009","title":"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 th…","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 th…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","cwe":["CWE-36"],"vendor":"WAVLINK Technology","product":"WN535M1","affected":["WN535M1 M35M1_V210223","WN535M3 M35M1_V210223"],"published":"2026-09-11","updated":"2026-09-15","sourceUpdated":"2026-09-15T17:17:32.830","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89009","references":[{"url":"https://docs.wavlink.xyz/","label":"disclosure@vulncheck.com"},{"url":"https://github.com/camdsmith/wavlink-sync_server-rce/blob/main/README.md","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/wavlink-wn535m1-wn535m3-unauthenticated-arbitrary-file-write-via-sync-server","label":"disclosure@vulncheck.com"},{"url":"https://github.com/camdsmith/wavlink-sync_server-rce/blob/main/README.md","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","cve.org","exploit-available"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-15T16:18:17.720897Z"},"epss":0.00676,"epssPercentile":0.50425,"ingestedAt":"2026-09-11T16:45:47.862Z","slug":"CVE-2026-89009","body":"## Overview\n\nWAVLINK 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"abyssal","depthScore":62,"depthScoreParts":{"impact":50.1,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":204294,"id":"CVE-2026-89009","ts":1789490449849,"field":"exploit_available","old":"false","new":"true"}]}