Vulnerability Description
Concorde, formerly know as Nexkey, is a fork of the federated microblogging platform Misskey. Due to a lack of CSRF countermeasures and improper settings of cookies for MediaProxy authentication, there is a vulnerability that allows MediaProxy authentication to be bypassed. In versions prior to 12.25Q1.1, the authentication cookie does not have the SameSite attribute. This allows an attacker to bypass MediaProxy authentication and load any image without restrictions under certain circumstances. In versions prior to 12.24Q2.3, this cookie was also used to authenticate the job queue management page (bull-board), so bull-board authentication is also bypassed. This may enable attacks that have a significant impact on availability and integrity. The affected versions are too old to be covered by this advisory, but the maintainers of Concorde strongly recommend not using older versions. Version 12.25Q1.1 contains a patch. There is no effective workaround other than updating.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/nexryai/concorde/commit/2309b4a292828ddba4d57cf0e914bc4330958
- https://github.com/nexryai/concorde/commit/f3f54bde6a37ad310f83ae46de54a286c4b74
- https://github.com/nexryai/concorde/security/advisories/GHSA-5hgq-9vw8-7v87
FAQ
What is CVE-2025-24900?
CVE-2025-24900 is a vulnerability with a CVSS score of 8.6 (HIGH). Concorde, formerly know as Nexkey, is a fork of the federated microblogging platform Misskey. Due to a lack of CSRF countermeasures and improper settings of cookies for MediaProxy authentication, ther...
How severe is CVE-2025-24900?
CVE-2025-24900 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-24900?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.