CVE-2022-31263Network attack vector

Account activation via stale email-domain validation

Published May 24, 2022 · Updated Aug 3, 2024

Email restriction bypass in Mastodon before 3.5.0 allows remote attackers to activate preregistered accounts from newly blocked domains. The User model applied BlacklistedEmailValidator only when an account was created, so an earlier confirmation token remained valid after an administrator blocked its email domain. Exploitation requires a pending account and its previously issued confirmation link, and the consequence is account activation despite the instance's domain restriction.

CVSS severity5.3
Medium
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Email restriction bypass in Mastodon before 3.5.0 allows remote attackers to activate preregistered accounts from newly blocked domains. The User model applied BlacklistedEmailValidator only when an account was created, so an earlier confirmation token remained valid after an administrator blocked its email domain. Exploitation requires a pending account and its previously issued confirmation link, and the consequence is account activation despite the instance's domain restriction.

The record

CVE
CVE-2022-31263
Published
May 24, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1136
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 24, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1136Create Account

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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