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Medium 4.8Published Mar 27, 2026

CVE-2026-33869Mastodon has a denial of service for quote authorization

Updated under an hour ago ()

Does this affect you?

It affects mastodon and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Mastodon 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.

CVSS
4.8 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
Weakness (CWE)
CWE-863
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
GitHub_M
NVD analysis
Analyzed
Record last updated
Mar 27, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
mastodon mastodon
mastodon:mastodon (from the name)
from 4.5.0, < 4.5.8; from 4.4.0, < 4.4.15
CNA record
joinmastodon mastodon
joinmastodon:mastodon
from 4.4.0 before 4.4.15; from 4.5.0 before 4.5.8
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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