Sensei LMS 4.26.4 Broken Access Control via save_new_message

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.

The Sensei LMS WordPress plugin before 4.26.4 contains a broken access control vulnerability in the legacy save_new_message handler hooked on the init action, which validates only a generic nonce without verifying course enrollment or restricting post_id to valid post types. Authenticated attackers, including unprivileged Subscribers, can supply an arbitrary post_id for any course, lesson, or quiz to create a private message addressed to that post's author, bypassing the enrollment checks enforced by the newer REST send-message controller.

Source published

19 Oct 2026 14:45:24 UTC

Source modified

27 Oct 2026 10:14:04 UTC

Observed here

27 Oct 2026 12:09:21 UTC

Source terms

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CVSS 4.0 · 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS 3.1 · 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N