CVE-2021-32802
There are several security concerns with passing user-generated content to this library, such as Server-Side-Request-Forgery, file disclosure or potentially executing code on the system.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Nextcloud server is an open source, self hosted personal cloud. Nextcloud supports rendering image previews for user provided file content. For some image types, the Nextcloud server was invoking a third-party library that wasn't suited for untrusted user-supplied content. There are several security concerns with passing user-generated content to this library, such as Server-Side-Request-Forgery, file disclosure or potentially executing code on the system. The risk depends on your system configuration and the installed library version. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0. These versions do not use this library anymore. As a workaround users may disable previews by setting `enable_previews` to `false` in `config.php`.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.60% probability · 85th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-829
- Affected
- nextcloud/nextcloud server
- Source
- security-advisories@github.com
EPSS 2.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://docs.nextcloud.com/server/21/admin_manual/configuration_files/previews_configuration.html#disabling-previewsVendor Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-m682-v4g9-wrq7Mitigation, Third Party Advisory
- https://hackerone.com/reports/1261413Permissions Required, Third Party Advisory
- https://security.gentoo.org/glsa/202208-17Third Party Advisory
- https://docs.nextcloud.com/server/21/admin_manual/configuration_files/previews_configuration.html#disabling-previewsVendor Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-m682-v4g9-wrq7Mitigation, Third Party Advisory
- https://hackerone.com/reports/1261413Permissions Required, Third Party Advisory
- https://security.gentoo.org/glsa/202208-17Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.