What is CVE-2022-24307?

CVE-2022-24307 is a critical-severity vulnerability in Joinmastodon Mastodon, classified under Incorrect Authorization. CVSS score: 9.8/10. Published 2022-02-03.

How severe is CVE-2022-24307?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Joinmastodon Mastodon

CVE-2022-24307

Mastodon before 3.3.2 and 3.4.x before 3.4.6 has incorrect access control because it does not compact incoming signed JSON-LD activities. (JSON-LD signing has been supported since version 1.6.0.)

Vulnerability class: Broken Access Control

Published 2022-02-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.015 (73.1th percentile), scored 2026-10-20.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 73.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.015 · change: +0.000

Affected products

Joinmastodon Mastodon

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

github.com/mastodon/mastodon/releases/tag/v3.4.6 (Third Party Advisory, Release Notes)
github.com/mastodon/mastodon/releases/tag/v3.3.2 (Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2022-24307?: CVE-2022-24307 is a critical-severity vulnerability in Joinmastodon Mastodon, classified under Incorrect Authorization. CVSS score: 9.8/10. Published 2022-02-03.
How severe is CVE-2022-24307?: Critical severity. CVSS v3 base score is 9.8 out of 10.