What is CVE-2023-36460?

CVE-2023-36460 is a critical-severity vulnerability in Joinmastodon Mastodon, classified under Path Traversal. CVSS score: 9.9/10. Published 2023-07-06.

How severe is CVE-2023-36460?

Critical severity. CVSS v3 base score is 9.9 out of 10.

Is CVE-2023-36460 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Path Traversal in Joinmastodon Mastodon

CVE-2023-36460

Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 3.5.0 and prior to versions 3.5.9, 4.0.5, and 4.1.3, attackers using carefully crafted media files can cause Mastodon's media processing code to create arbitrary files at any location. This allows attackers to create and overwrite any file Mastodon has access to, allowing Denial of Service and arbitrary Remote Code Execution. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2023-07-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.401 (98.6th percentile), scored 2026-10-20.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 99th percentile — 98.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.401 · newest: 0.401 · change: 0.000

Affected products

Joinmastodon Mastodon
Mastodon — versions >= 3.5.0, < 3.5.9, >= 4.0.0, < 4.0.5, >= 4.1.0, < 4.1.3

Weakness classification (CWE)

CWE-22 — Path Traversal

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

github.com/mastodon/mastodon/security/advisories/GHSA-9928-3cp5-93fm (Third Party Advisory)
github.com/mastodon/mastodon/commit/dc8f1fbd976ae544720a4e07120d9a91b2722440 (Patch, Third Party Advisory)
github.com/mastodon/mastodon/releases/tag/v3.5.9 (Third Party Advisory)
github.com/mastodon/mastodon/releases/tag/v4.0.5 (Third Party Advisory)
github.com/mastodon/mastodon/releases/tag/v4.1.3 (Third Party Advisory)
www.openwall.com/lists/oss-security/2023/07/06/4 (Mailing List)

Frequently asked questions

What is CVE-2023-36460?: CVE-2023-36460 is a critical-severity vulnerability in Joinmastodon Mastodon, classified under Path Traversal. CVSS score: 9.9/10. Published 2023-07-06.
How severe is CVE-2023-36460?: Critical severity. CVSS v3 base score is 9.9 out of 10.
Is CVE-2023-36460 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.