CVE-2022-0903Network attack vector

Unauthenticated server crash via SAML POST stack exhaustion

Published Mar 9, 2022 · Updated Dec 6, 2024

Call stack overflow in Mattermost Server 6.3.2 and earlier allows remote attackers to crash the server through a crafted SAML login POST. The SAML login request path accepts a malicious POST body that exhausts the Go goroutine call stack; public records do not identify the recursive parser or function responsible. Authentication is not required, but the SAML login feature must be reachable, and the demonstrated consequence is a server crash rather than data modification.

CVSS severity5.3
Medium
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Call stack overflow in Mattermost Server 6.3.2 and earlier allows remote attackers to crash the server through a crafted SAML login POST. The SAML login request path accepts a malicious POST body that exhausts the Go goroutine call stack; public records do not identify the recursive parser or function responsible. Authentication is not required, but the SAML login feature must be reachable, and the demonstrated consequence is a server crash rather than data modification.

The record

CVE
CVE-2022-0903
Published
Mar 9, 2022
Updated
Dec 6, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 9, 2022CVE 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=5.37 <5.37.8
  2. Affected versionversion=6.1 <6.1.3
  3. Affected versionversion=6.2 <6.2.3
  4. Affected versionversion=6.3 <6.3.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mattermost · Mattermostversion=5.37 <5.37.8; version=6.1 <6.1.3; version=6.2 <6.2.3; version=6.3 <6.3.3

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.3Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 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-787Out-of-bounds Write
T1499.004Application or System Exploitation

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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