CVE-2022-21706Network attack vector

Cross-organization access via unchecked invitation realm

Published Feb 25, 2022 · Updated Apr 23, 2025

Authorization bypass in Zulip Server 2.0.0 through 4.9 allows remote attackers to join another organization through a reusable invite. The accounts_home_from_multiuse_invite and maybe_send_to_registration paths accepted a multi-use invite without matching its realm to the requested realm. A deployment must host multiple organizations, and possession of an invite from one organization is enough to bypass invitation or email-domain controls and inherit its assigned role in another.

CVSS severity7.2
High
EPSS probability1.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Zulip Server 2.0.0 through 4.9 allows remote attackers to join another organization through a reusable invite. The accounts_home_from_multiuse_invite and maybe_send_to_registration paths accepted a multi-use invite without matching its realm to the requested realm. A deployment must host multiple organizations, and possession of an invite from one organization is enough to bypass invitation or email-domain controls and inherit its assigned role in another.

The record

CVE
CVE-2022-21706
Published
Feb 25, 2022
Updated
Apr 23, 2025
Vendor
Zulip
Product
Zulip
Classifications
CWE-863, CWE-284, T1136
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 25, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.0.0, < 4.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zulip · Zulipversion=>= 2.0.0, < 4.10

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.2GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

CWE-863Incorrect Authorization
CWE-284Improper Access Control
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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