Medium (4.3) in open-xchange open-xchange appsuite backend. EPSS 0.8% chance of exploitation in the next 30 days.
IPv4-mapped IPv6 addresses did not get recognized as "local" by the code and a connection attempt is made. Attackers with access to user accounts could use this to bypass existing deny-list functionality and trigger requests to restricted network infrastructure to gain insight about topology and running services. We now respect possible IPV4-mapped IPv6 addresses when checking if contained in a deny-list. No publicly available exploits are known.
Severity
CVSS 3.1
4.3 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS
0.8% chance of exploitation in the next 30 days; higher than 57% of CVEs (scores of 2026-10-31)