CVE-2021-39195
mediumpriority · track · 26EPSS 0.011 · 64 %ileEUUSEPSS · scored 2026-10-28
Misskey is an open source, decentralized microblogging platform. In affected versions a Server-Side Request Forgery vulnerability exists in "Upload from URL" and remote attachment handling. This could result in the disclosure of non-public information within the internal network. This has been fixed in 12.90.0. However, if you are using a proxy, you will need to take additional measures. As a workaround this exploit may be avoided by appropriately restricting access to private networks from the host where the application is running.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4–7.7
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (2)
Products and version ranges known to be affected.
also known as (2)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (11)
External citations — patches, advisories, analysis.
- https://github.com/misskey-dev/misskey/blob/develop/CHANGELOG.md#12900-20210904cnnvd
- https://github.com/misskey-dev/misskey/commit/e1a8b158e04ad567d92d8daf3cc0898ee18f1a2ecnnvd
- https://github.com/misskey-dev/misskey/security/advisories/GHSA-mqv7-gxh4-r5vfcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2021-39195cnnvd
- https://www.cybersecurity-help.cz/vdb/SB2021091012cnnvd
- https://github.com/misskey-dev/misskey/blob/develop/CHANGELOG.md#12900-20210904enisa_euvd
- https://github.com/misskey-dev/misskey/commit/e1a8b158e04ad567d92d8daf3cc0898ee18f1a2eenisa_euvd
- https://github.com/misskey-dev/misskey/security/advisories/GHSA-mqv7-gxh4-r5vfenisa_euvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan