CVE-2024-39836
Munged email address used for password resets and notifications
Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to ensure that remote/synthetic users cannot create sessions or reset passwords, which allows the munged email addresses, created by shared channels, to be used to receive email notifications and to reset passwords, when they are valid, functional emails.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Munged email address used for password resets and notifications
Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to ensure that remote/synthetic users cannot create sessions or reset passwords, which allows the munged email addresses, created by shared channels, to be used to receive email notifications and to reset passwords, when they are valid, functional emails.
- Record
CVE-2024-39836- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-693
- Updated
- 2026-11-02
EUVDEUVD-2024-2555
Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to ensure that remote/synthetic users cannot create sessions or reset passwords, which allows the munged email addresses, created by shared channels, to be used to receive email notifications and to reset passwords, when they are valid, functional emails.
- Record
EUVD-2024-2555- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-c6vp-jjgv-38wj
Mattermost allows remote/synthetic users to create sessions, reset passwords
Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to ensure that remote/synthetic users cannot create sessions or reset passwords, which allows the munged email addresses, created by shared channels, to be used to receive email notifications and to reset passwords, when they are valid, functional emails.
- Record
GHSA-c6vp-jjgv-38wj- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-693
- Updated
- 2026-11-02
NVD
Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to ensure that remote/synthetic users cannot create sessions or reset passwords, which allows the munged email addresses, created by shared channels, to be used to receive email notifications and to reset passwords, when they are valid, functional emails.
- Record
CVE-2024-39836- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-693
- Updated
- 2026-11-02
OSV
Munged email address used for password resets and notifications
Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to ensure that remote/synthetic users cannot create sessions or reset passwords, which allows the munged email addresses, created by shared channels, to be used to receive email notifications and to reset passwords, when they are valid, functional emails.
- Record
CVE-2024-39836- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-693
- Updated
- 2026-11-02
OSVGHSA-c6vp-jjgv-38wj
Mattermost allows remote/synthetic users to create sessions, reset passwords
Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 and 9.8.x <= 9.8.2 fail to ensure that remote/synthetic users cannot create sessions or reset passwords, which allows the munged email addresses, created by shared channels, to be used to receive email notifications and to reset passwords, when they are valid, functional emails.
- Record
GHSA-c6vp-jjgv-38wj- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-693
- Updated
- 2026-11-02
OSVGO-2024-3096 No score
Mattermost allows remote/synthetic users to create sessions, reset passwords in github.com/mattermost/mattermost-server
Mattermost allows remote/synthetic users to create sessions, reset passwords in github.com/mattermost/mattermost-server
- Record
GO-2024-3096- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/mattermost/mattermost/server/v8Go |
9.9.0 up to 9.9.2 | 9.9.2 |
github.com/mattermost/mattermost/server/v8Go |
9.5.0 up to 9.5.8 | 9.5.8 |
github.com/mattermost/mattermost/server/v8Go |
9.10.0 up to 9.10.1 | 9.10.1 |
github.com/mattermost/mattermost/server/v8Go |
9.8.0 up to 9.8.3 | 9.8.3 |
github.com/mattermost/mattermost-serverGo |
9.5.0+incompatible up to 9.5.8+incompatible, 9.8.0+incompatible up to 9.8.3+incompatible, 9.9.0+incompatible up to 9.9.2+incompatible, 9.10.0+incompatible up to 9.10.1+incompatible | 9.5.8+incompatible9.8.3+incompatible9.9.2+incompatible9.10.1+incompatible |
github.com/mattermost/mattermost-server/v5Go |
All versions | None known |
github.com/mattermost/mattermost-server/v6Go |
All versions | None known |
github.com/mattermost/mattermost/server/v8Go |
All versions | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-39836 is a medium vulnerability (CVSS 4.8) in Mattermost, published August 22, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 18th percentile. Fixed in github.com/mattermost/mattermost/server/v8 9.9.2.