What is CVE-2026-50128?

CVE-2026-50128 is a medium-severity vulnerability in Mastodon, classified under Improper Validation of Integrity Check Value. CVSS score: 5.3/10. Published 2026-06-24.

How severe is CVE-2026-50128?

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

Vulnerability in Mastodon

CVE-2026-50128

Mastodon is a free, open-source social network server based on ActivityPub. From 4.3.0 until 4.5.11 and 4.4.18, Mastodon has a feature to let websites credit authors of their articles. To prevent false attribution claims, Mastodon uses the…

EPSS: 0.001 (2.9th percentile) — read the EPSS interpretation.

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.

Affected products

Mastodon — versions >= 4.5.0-beta.1, < 4.5.11, >= 4.3.0, < 4.4.18

Weakness classification (CWE)

CWE-354 — Improper Validation of Integrity Check Value

References

security-advisories@github.com (x_refsource_CONFIRM)
134c704f-9b21-4f2e-91b3-4a467353bcc0

Frequently asked questions

What is CVE-2026-50128?: CVE-2026-50128 is a medium-severity vulnerability in Mastodon, classified under Improper Validation of Integrity Check Value. CVSS score: 5.3/10. Published 2026-06-24.
How severe is CVE-2026-50128?: Medium severity. CVSS v3 base score is 5.3 out of 10.