FileRise < 3.28.0 Privilege Escalation via WebDAV Session Inheritance

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.

FileRise before version 3.28.0 contains a privilege escalation vulnerability that allows authenticated low-privilege attackers to gain unauthorized read and write access by exploiting improper session isolation between the WebDAV interface and the web application session context. Attackers can combine valid Basic-Auth credentials with an active admin PHPSESSID cookie to bypass authorization boundaries, as the WebDAV layer incorrectly inherits elevated privileges from an ambient web session rather than enforcing independent stateless authentication per RFC 4918.

Source published

16 Sep 2026 14:38:11 UTC

Source modified

1 Oct 2026 15:21:55 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 7.6 CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS 3.1 · 6.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N