CVE-2023-42450
Mastodon Server-Side Request Forgery vulnerability
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes ALLOWED_PRIVATE_ADDRESSES to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.
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
Mastodon Server-Side Request Forgery vulnerability
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes ALLOWED_PRIVATE_ADDRESSES to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.
- Record
CVE-2023-42450- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-918, CWE-113
- Updated
- 2026-11-02
EUVDEUVD-2023-46896
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes ALLOWED_PRIVATE_ADDRESSES to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.
- Record
EUVD-2023-46896- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
NVD
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes ALLOWED_PRIVATE_ADDRESSES to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.
- Record
CVE-2023-42450- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-113, CWE-918
- Updated
- 2026-11-02
OSV
Mastodon Server-Side Request Forgery vulnerability
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes ALLOWED_PRIVATE_ADDRESSES to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.
- Record
CVE-2023-42450- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-113, CWE-918
- Updated
- 2026-11-02
OSVBIT-mastodon-2023-42450 No score
Mastodon Server-Side Request Forgery vulnerability
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes ALLOWED_PRIVATE_ADDRESSES to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.
- Record
BIT-mastodon-2023-42450- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mastodonBitnami |
4.2.0-beta1 up to 4.2.0, 4.2.0-beta2 up to 4.2.0, 4.2.0-beta3 up to 4.2.0, 4.2.0-rc1 up to 4.2.0 | 4.2.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-42450 is a medium vulnerability (CVSS 5.4) in Joinmastodon Mastodon, published September 19, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.46%, the 40th percentile. Fixed in mastodon 4.2.0.