CVE-2025-67500Mastodon is a free, open-source social network server based on ActivityPub.
Updated under an hour ago ()
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It affects joinmastodon mastodon. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
Mastodon is a free, open-source social network server based on ActivityPub. Versions 4.2.27 and prior, 4.3.0-beta.1 through 4.3.14, 4.4.0-beta.1 through 4.4.9, 4.5.0-beta.1 through 4.5.2 have discrepancies in error handling which allow checking whether a given status exists by sending a request with a non-English Accept-Language header. Using this behavior, an attacker who knows the identifier of a particular status they are not allowed to see can confirm whether this status exists or not. This cannot be used to learn the contents of the status or any other property besides its existence. This issue is fixed in versions 4.2.28, 4.3.15, 4.4.10 and 4.5.3.
- CVSS
- 3.7 LOW (v3.1, NVD)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- Weakness (CWE)
- CWE-204
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
joinmastodon mastodon joinmastodon:mastodon | before 4.2.28; from 4.3.0 before 4.3.15; from 4.4.0 before 4.4.10; from 4.5.0 before 4.5.3 | NVD |
References
- https://github.com/mastodon/mastodon/pull/37077/commits/9957d3218cb33fea6a44bb285e2ba4795a059e4fpatch
- https://github.com/mastodon/mastodon/security/advisories/GHSA-gwhw-gcjx-72v8vendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.