Mastodon has a denial of service for quote authorization

MITRE NVD CVE.ORG Print: PDF PDF

Summary

CVECVE-2026-33869
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-03-27 20:16:34 UTC
Updated2026-03-30 19:12:07 UTC
DescriptionMastodon is a free, open-source social network server based on ActivityPub. In versions on the 4.5.x branch prior to 4.5.8 and on the 4.4.x branch prior to 4.4.15, an attacker that knows of a quote before it has reached a server can prevent it from being correctly processed on that server. The vulnerability has been patched in Mastodon 4.5.8 and 4.4.15. Mastodon 4.3 and earlier are not affected because they do not support quotes.

Risk And Classification

Primary CVSS: v3.1 4.8 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

Problem Types: CWE-863 | CWE-863 CWE-863: Incorrect Authorization

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary4.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
3.1CNADECLARED4.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Joinmastodon Mastodon All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Mastodon Mastodon affected >= 4.5.0, < 4.5.8 Not specified
CNA Mastodon Mastodon affected >= 4.4.0, < 4.4.15 Not specified

References

ReferenceSourceLinkTags
github.com/mastodon/mastodon/security/advisories/GHSA-q4g8-82c5-9h33 [email protected] github.com Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
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