CVE-2023-1421Network attack vector

Victim-context AJAX requests via reflected OAuth state

Published Mar 15, 2023 · Updated Dec 6, 2024

Reflected XSS in Mattermost 5.32.0 through versions before 7.7 allows remote authenticated users to issue AJAX requests as a victim. The OAuth flow completion endpoints reflect a malicious state parameter into the generated page without neutralizing active browser content. Exploitation requires a signed-in victim to open the crafted link, and Mattermost's assessment limits the reported consequence to access to victim-visible data.

CVSS severity3.5
Low
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Mattermost 5.32.0 through versions before 7.7 allows remote authenticated users to issue AJAX requests as a victim. The OAuth flow completion endpoints reflect a malicious state parameter into the generated page without neutralizing active browser content. Exploitation requires a signed-in victim to open the crafted link, and Mattermost's assessment limits the reported consequence to access to victim-visible data.

The record

CVE
CVE-2023-1421
Published
Mar 15, 2023
Updated
Dec 6, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 6, 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?

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

  1. Affected versionversion=5.32.0 <7.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=5.32.0 <7.7

Published CVSS scores

3.5Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001User Execution: Malicious Link

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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