What is CVE-2026-30878?

CVE-2026-30878 is a medium-severity vulnerability in Basercms, classified under Improper Authorization. CVSS score: 5.3/10. Published 2026-03-31.

How severe is CVE-2026-30878?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Auth bypass in Basercms

CVE-2026-30878

baserCMS is a website development framework. Prior to version 5.2.3, a public mail submission API allows unauthenticated users to submit mail form entries even when the corresponding form is not accepting submissions. This bypasses administrative controls intended to stop form intake and enables spam or abuse via the API. This issue has been patched in version 5.2.3.

Published 2026-03-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (36.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Basercms
Baserproject Basercms — versions < 5.2.3

Weakness classification (CWE)

CWE-285 — Improper Authorization

References

github.com/baserproject/basercms/security/advisories/GHSA-8cr7-r8qw-gp3c (Exploit, Vendor Advisory)
basercms.net/security/JVN_20837860 (Vendor Advisory)
github.com/baserproject/basercms/releases/tag/5.2.3 (Release Notes)

Frequently asked questions

What is CVE-2026-30878?: CVE-2026-30878 is a medium-severity vulnerability in Basercms, classified under Improper Authorization. CVSS score: 5.3/10. Published 2026-03-31.
How severe is CVE-2026-30878?: Medium severity. CVSS v3 base score is 5.3 out of 10.