CVE-2026-50128

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Source
https://cve.org/CVERecord?id=CVE-2026-50128
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50128.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-50128
Aliases
Related
Published
2026-06-24T19:48:52.942Z
Modified
2026-07-15T01:49:02.209953141Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
Summary
Mastodon: Spoofing of attribution domains
Details

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.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50128.json",
    "cwe_ids": [
        "CWE-354"
    ],
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/mastodon/mastodon

Affected ranges

Type
GIT
Repo
https://github.com/mastodon/mastodon
Events
Introduced
5a8ab0a3e62a8825e28bb74c1760ba6488d20c97
Fixed
0748a5ff81b24e666ab10b8ee7fbc6f0362c8cb0
Introduced
ab36c152f9e5f9054798504354365dcaef4e5c43
Fixed
3555d595e2a6fcf425c73f783e8709b1e44c0872
Database specific 
{
    "extracted_events": [
        {
            "introduced": "4.5.0-beta.1"
        },
        {
            "fixed": "4.5.11"
        },
        {
            "introduced": "4.3.0"
        },
        {
            "fixed": "4.4.18"
        }
    ],
    "source": "AFFECTED_FIELD"
}

Affected versions

v4.*
v4.5.0
v4.5.0-beta.1
v4.5.0-beta.2
v4.5.0-rc.1
v4.5.0-rc.2
v4.5.0-rc.3
v4.5.1
v4.5.10
v4.5.2
v4.5.3
v4.5.4
v4.5.5
v4.5.6
v4.5.7
v4.5.8
v4.5.9

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50128.json"