Mastodon is a free, open-source social network server based on ActivityPub. From 4.3.0 until 4.5.11 and 4.4.18, Mastodon has a feature to let websites credit authors of their articles. To prevent false attribution claims, Mastodon uses the attributionDomains JSON-LD term, however, an error in how it is defined makes Linked Data Signatures on the toot:attributionDomains property ineffective. An attacker can arbitrarily modify the attributionDomains value of a legitimately signed Update activity and bypass Mastodon’s signature verification. This vulnerability is fixed in 4.5.11 and 4.4.18.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 25 Jun 2026 16:30:00 +0000
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ssvc
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Thu, 25 Jun 2026 13:30:00 +0000
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Joinmastodon
Joinmastodon mastodon |
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Joinmastodon
Joinmastodon mastodon |
Wed, 24 Jun 2026 20:30:00 +0000
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| Description | Mastodon is a free, open-source social network server based on ActivityPub. From 4.3.0 until 4.5.11 and 4.4.18, Mastodon has a feature to let websites credit authors of their articles. To prevent false attribution claims, Mastodon uses the attributionDomains JSON-LD term, however, an error in how it is defined makes Linked Data Signatures on the toot:attributionDomains property ineffective. An attacker can arbitrarily modify the attributionDomains value of a legitimately signed Update activity and bypass Mastodon’s signature verification. This vulnerability is fixed in 4.5.11 and 4.4.18. | |
| Title | Mastodon: Spoofing of attribution domains | |
| Weaknesses | CWE-354 | |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-06-25T15:40:03.219Z
Reserved: 2026-06-03T18:49:32.275Z
Link: CVE-2026-50128
Updated: 2026-06-25T15:39:45.433Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-06-25T13:15:03Z
Weaknesses