CVE-2026-25540
Feb. 5, 2026, 2:57 p.m.
6.5
Medium
Description
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.3.19, 4.4.13, 4.5.6, Mastodon is vulnerable to web cache poisoning via `Rails.cache. When AUTHORIZED_FETCH is enabled, the ActivityPub endpoints for pinned posts and featured hashtags have contents that depend on the account that signed the HTTP request. However, these contents are stored in an internal cache and reused with no regards to the signing actor. As a result, an empty response generated for a blocked user account may be served to requests from legitimate non-blocked actors, or conversely, content intended for non-blocked actors may be returned to blocked actors. This issue has been patched in versions 4.3.19, 4.4.13, 4.5.6.
Product(s) Impacted
| Vendor | Product | Versions |
|---|---|---|
| Mastodon |
|
|
Weaknesses
Common security weaknesses mapped to this vulnerability.
CWE-524
Use of Cache Containing Sensitive Information
The code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere.
*CPE(s)
Affected systems and software identified for this CVE.
| Type | Vendor | Product | Version | Update | Edition | Language | Software Edition | Target Software | Target Hardware | Other Information |
|---|---|---|---|---|---|---|---|---|---|---|
| a | mastodon | mastodon | <4.3.19 | / | / | / | / | / | / | / |
| a | mastodon | mastodon | <4.4.13 | / | / | / | / | / | / | / |
| a | mastodon | mastodon | <4.5.6 | / | / | / | / | / | / | / |
Tags
CVSS Score
CVSS Data - 3.1
- Attack Vector: NETWORK
- Attack Complexity: LOW
- Privileges Required: NONE
- Scope: UNCHANGED
- Confidentiality Impact: LOW
- Integrity Impact: NONE
- Availability Impact: LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
Timeline
Published: Feb. 4, 2026, 10:16 p.m.
Last Modified: Feb. 5, 2026, 2:57 p.m.
Last Modified: Feb. 5, 2026, 2:57 p.m.
Status : Awaiting Analysis
CVE has been recently published to the CVE List and has been received by the NVD.
More infoSource
*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.