Signal is active with 1 mentions in latest observed window
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NVD 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.
Priority
LOW
Exploitation
NONE
PoC
NONE
Patch
NONE
Momentum
NONE
If you run products in this scope, you should treat this CVE as relevant to your environment.
CVE-2026-25540 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… https://www.cve.org/CVERecord?id=CVE-2026-25540
Post summary
The text announces a new CVE (CVE-2026-25540) affecting Mastodon versions prior to 4.3.19, 4.4.13, and 4.5.6, detailing a web cache poisoning vulnerability with a link to the official CVE record.
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| Part | Vendor | Product | Version | Target SW | Target HW |
|---|---|---|---|---|---|
| App | joinmastodon | mastodon | - | - | - |