What is CVE-2026-27468?

CVE-2026-27468 is a high-severity vulnerability in Joinmastodon Mastodon, classified under Missing Authorization. CVSS score: 8.2/10. Published 2026-02-24.

How severe is CVE-2026-27468?

High severity. CVSS v3 base score is 8.2 out of 10.

Auth bypass in Joinmastodon Mastodon

CVE-2026-27468

Mastodon is a free, open-source social network server based on ActivityPub. FASP registration requires manual approval by an administrator. In versions 4.4.0 through 4.4.13 and 4.5.0 through 4.5.6, actions performed by a FASP to subscribe…

Vulnerability class: Broken Access Control

EPSS: 0.002 (15.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H.

Affected products

Joinmastodon Mastodon
Mastodon — versions >= 4.4.0, < 4.4.14, >= 4.5.0, < 4.5.7

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-27468?: CVE-2026-27468 is a high-severity vulnerability in Joinmastodon Mastodon, classified under Missing Authorization. CVSS score: 8.2/10. Published 2026-02-24.
How severe is CVE-2026-27468?: High severity. CVSS v3 base score is 8.2 out of 10.