CVE-2022-31017Network attack vector

Protected-history disclosure via message edit events

Published Jun 25, 2022 · Updated Apr 23, 2025

Information disclosure in Zulip Server 2.1.0 through 5.2 allows remote authenticated users to read protected stream history via edit events. The message-edit event path sends both old and edited content to every current stream subscriber without checking whether each recipient can view the original message. Exploitation requires membership in a private protected-history stream, a later edit to a pre-subscription message, and inspection through a modified client or developer tools.

CVSS severity2.0
Low
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Zulip Server 2.1.0 through 5.2 allows remote authenticated users to read protected stream history via edit events. The message-edit event path sends both old and edited content to every current stream subscriber without checking whether each recipient can view the original message. Exploitation requires membership in a private protected-history stream, a later edit to a pre-subscription message, and inspection through a modified client or developer tools.

The record

CVE
CVE-2022-31017
Published
Jun 25, 2022
Updated
Apr 23, 2025
Vendor
Zulip
Product
Zulip
Classifications
CWE-571, CWE-670, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 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=>= 2.1.0, < 5.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Zulip · Zulipversion=>= 2.1.0, < 5.3

Published CVSS scores

2.0GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N
2.1NIST NVDAV:N/AC:H/Au:S/C:P/I:N/A:N
2.6NIST NVDCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-571Expression is Always True
CWE-670Always-Incorrect Control Flow Implementation
T1213Data from Information Repositories

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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