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CVE-2023-43754

Permalink previews displayed for posts in archived channels even if users are disallowed to view archived channels

4.3 MediumFix available

Mattermost fails to check whether the  “Allow users to view archived channels”  setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the “Allow users to view archived channels” setting is disabled.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
Low
User interaction
None

What an attacker can affect

Confidentiality
Low
Integrity
None
Availability
None

Exploit likelihood

0.51%Up 0.5 points since Nov 28, 2023
90%50%10%1%

What each source reports

CVE List Score used 4.3

Permalink previews displayed for posts in archived channels even if users are disallowed to view archived channels

Mattermost fails to check whether the  “Allow users to view archived channels”  setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the “Allow users to view archived channels” setting is disabled. 

Record
CVE-2023-43754
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-200
Updated
2026-11-02
EUVDEUVD-2023-2991 4.3

Mattermost fails to check whether the  “Allow users to view archived channels”  setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the “Allow users to view archived channels” setting is disabled. 

Record
EUVD-2023-2991
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Updated
2026-11-03
GitHub AdvisoriesGHSA-jjr7-372r-cx7x 4.3

Mattermost Exposure of Sensitive Information to an Unauthorized Actor vulnerability

Mattermost fails to check whether the "Allow users to view archived channels" setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the "Allow users to view archived channels" setting is disabled. 

Record
GHSA-jjr7-372r-cx7x
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-200
Updated
2026-11-02
NVD 4.3

Mattermost fails to check whether the  “Allow users to view archived channels”  setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the “Allow users to view archived channels” setting is disabled. 

Record
CVE-2023-43754
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-200
Updated
2026-11-02
OSV 4.3

Permalink previews displayed for posts in archived channels even if users are disallowed to view archived channels

Mattermost fails to check whether the  “Allow users to view archived channels”  setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the “Allow users to view archived channels” setting is disabled. 

Record
CVE-2023-43754
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-200
Updated
2026-11-02
OSVGHSA-jjr7-372r-cx7x 4.3

Mattermost Exposure of Sensitive Information to an Unauthorized Actor vulnerability

Mattermost fails to check whether the "Allow users to view archived channels" setting is enabled during permalink previews display, allowing members to view permalink previews of archived channels even if the "Allow users to view archived channels" setting is disabled. 

Record
GHSA-jjr7-372r-cx7x
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-200
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
github.com/mattermost/mattermost/server/v8
Go
9.1.0 up to 9.1.1
9.1.1
github.com/mattermost/mattermost/server/v8
Go
9.0.0 up to 9.0.2
9.0.2
github.com/mattermost/mattermost/server/v8
Go
before 8.1.4
8.1.4
github.com/mattermost/mattermost-server/v6
Go
before 7.8.13
7.8.13

History

History
RecordedChangedSources
aliases, publishedEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2023-43754 is a medium vulnerability (CVSS 4.3) in Mattermost, published November 27, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.51%, the 43rd percentile. Fixed in github.com/mattermost/mattermost/server/v8 9.1.1.

References

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