CVE-2026-47777
highpriority · track · 10OT risk · elevatedEPSS 0.002 · 6 %ileexploit · PoCEUUSEPSS · scored 2026-10-27
Mastodon is a free, open-source social network server based on ActivityPub. In versions there is a missing condition in the check if remote accounts consented to be featured in a remote Collection could lead to attackers bypassing the check and faking consent. An attacker could forge the FeatureAuthorization object that is used to verify consent to be featured in a Collection and thus make it appear as if an account is allowed to be in a Collection when it actually is not. While the FeatureAuthorization must reside on the same domain as the object it is for, a check is missing to make sure said object is actually the same as in the Collection item. This allows an attacker to forge the authorization. Mastodon servers are affected only if running the main branch or nightly builds who have opted into testing the experimental "Collections" feature by setting the environment variable EXPERIMENTAL_FEATURES to a value including collections. This has been patched in version 4.6.0-beta.1.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (1)
Public proof-of-concept and weaponised exploit code.
- bekwiner/cve-2026-47777bekwiner/cve-2026-47777PoC · poc_in_github
affected products (2)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- BIT-mastodon-2026-47777Mastodon has a consent-check bypass in its remote Collections2026-06-18vendor · osvUS
Mastodon is a free, open-source social network server based on ActivityPub. In versions there is a missing condition in the check if remote accounts consented to be featured in a remote Collection could lead to attackers bypassing the check and faking consent. An attacker could forge the FeatureAuthorization object that is used to verify consent to be featured in a Collection and thus make it appear as if an account is allowed to be in a Collection when it actually is not. While the FeatureAuthorization must reside on the same domain as the object it is for, a check is missing to make sure said object is actually the same as in the Collection item. This allows an attacker to forge the authorization. Mastodon servers are affected only if running the main branch or nightly builds who have opted into testing the experimental "Collections" feature by setting the environment variable EXPERIMENTAL_FEATURES to a value including collections. This has been patched in version 4.6.0.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://github.com/mastodon/mastodon/commit/22203f8aeb03e8f14dc62e253e83db39825a5bcfcnnvd
- https://github.com/mastodon/mastodon/security/advisories/GHSA-vg36-gxjg-2v46cnnvd
- https://github.com/mastodon/mastodon/commit/22203f8aeb03e8f14dc62e253e83db39825a5bcfenisa_euvd
- https://github.com/mastodon/mastodon/security/advisories/GHSA-vg36-gxjg-2v46enisa_euvd
- https://github.com/mastodon/mastodon/commit/22203f8aeb03e8f14dc62e253e83db39825a5bcfnvd
- https://github.com/mastodon/mastodon/security/advisories/GHSA-vg36-gxjg-2v46nvd
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