FreeMail before 5.3.2 Authorization Bypass via /api/create Mailbox Claiming

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

FreeMail before 5.3.2 contains an authorization bypass vulnerability that allows authenticated users to claim another user's existing mailbox via the POST /api/create endpoint. Attackers who know a victim's address can become co-owners through assignMailboxToUser to read messages and verification codes, set forwarding, and delete mail.

Source published

29 Oct 2026 13:08:50 UTC

Source modified

29 Oct 2026 14:02:26 UTC

Observed here

29 Oct 2026 16:12:12 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 7.2 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N

CVSS 3.1 · 7.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L