Vulnerability · Published Mar 5, 2026 · Assigned by NCSC.ch
CVE-2026-2743SEPPmail User Web Interface Arbitrary File Write to RCE
Critical 10.0
In plain English
A critical-severity path traversal in SeppMail from SeppMail. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities).
Severity (CVSS 4.0)10.0Critical
Exploit odds (30 days)0.9%top 38.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
Arbitrary File Write via Path Traversal upload to Remote Code Execution in SeppMail User Web Interface. The affected feature is the large file transfer (LFT). This issue affects SeppMail: 15.0.2.1 and before
Affected products (as reported)
Weakness: CWE-22, CWE-434 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/AU:Y