CVE-2024-42406

Unauthorized access on archived channels

MEDIUM

5.4

CVSS Score

Published: September 26, 2024 at 08:04 AM UTC

Updated: June 17, 2026 at 07:49 AM UTC

2 products affected across 1 vendorMattermost ServerMattermost

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Severity

MEDIUM5.4

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

Description

Mattermost versions 9.11.x <= 9.11.0, 9.10.x <= 9.10.1, 9.9.x <= 9.9.2 and 9.5.x <= 9.5.8 fail to properly authorize requests when viewing archived channels is disabled, which allows an attacker to retrieve post and file information about archived channels. Examples are flagged or unread posts as well as files.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Mattermost Server · Mattermost

95%

9.10.0 ≤ v < 9.10.29.5.0 ≤ v < 9.5.99.9.0 ≤ v < 9.9.39.11.0 9.11.0 rc1 9.11.0 rc2 9.11.0 rc3

Affected range stops below 9.10.2, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.5.9, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.9.3, so it looks safe — our inference, not a vendor statement

Mattermost · Mattermost

60%

9.10.0 ≤ v ≤ 9.10.19.5.0 ≤ v ≤ 9.5.89.9.0 ≤ v ≤ 9.9.29.10.0 9.11.0 9.5.0 9.9.0

Vendor states this is fixed in 10.0.0 (unaffected)

Vendor states this is fixed in 9.10.2 (unaffected)

Vendor states this is fixed in 9.11.1 (unaffected)

Vendor states this is fixed in 9.5.9 (unaffected)

Vendor states this is fixed in 9.9.3 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://mattermost.com/security-updates

References (1)

Vendor Advisory

Source: [email protected]

https://mattermost.com/security-updates

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.4MEDIUMMattermost

Attack Vector: NETWORK
Complexity: LOW
Privileges: LOW
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: LOW
Integrity: LOW
Availability: NONE

Vector?

Quick Info

StatusANALYZED

CWE

CWE-284NVD-CWE-noinfo

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