CVE-2023-5969Network attack vector

Service interruption via unbounded redirect cache entries

Published Nov 6, 2023 · Updated Sep 17, 2024

Resource exhaustion in affected Mattermost releases allows remote attackers to exhaust server memory via a crafted API request. The unauthenticated /api/v4/redirect_location handler fails to bound attacker-controlled data before retaining large items in its cache. Network reachability to the endpoint is sufficient; repeated crafted requests consume memory and can interrupt the Mattermost service without affecting data confidentiality or integrity.

CVSS severity5.3
Medium
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Resource exhaustion in affected Mattermost releases allows remote attackers to exhaust server memory via a crafted API request. The unauthenticated /api/v4/redirect_location handler fails to bound attacker-controlled data before retaining large items in its cache. Network reachability to the endpoint is sufficient; repeated crafted requests consume memory and can interrupt the Mattermost service without affecting data confidentiality or integrity.

The record

CVE
CVE-2023-5969
Published
Nov 6, 2023
Updated
Sep 17, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 6, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <=7.8.11
  2. Affected versionversion=0 <=8.0.3
  3. Affected versionversion=0 <=8.1.2
  4. Affected versionversion=0 <=9.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mattermost · Mattermostversion=0 <=7.8.11; version=0 <=8.0.3; version=0 <=8.1.2; version=0 <=9.0.0

Published CVSS scores

5.3Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo