CVE-2026-57575
MediumCVSS 6.9Exploitation Probability (EPSS)
Low risk27th percentile - higher than 27% of all known CVEs
Summary
Misskey prior to version 2026.6.0 contains a Server-Side Request Forgery (SSRF) vulnerability in the URL preview functionality. Missing network restrictions before establishing outbound connections allow a remote attacker to send HTTP requests to loopback, private, or link-local services.
Risk Assessment
The risk involves potential scanning of internal network infrastructure by an attacker, but due to IP address validation occurring after the request is sent, no sensitive internal data is believed to be exposed.
Recommendation
Immediately upgrade Misskey to version 2026.6.0 or later, which includes a fix for the SSRF vulnerability.
Other vulnerabilities in Misskey
See all- CVE-2026-46713Critical
Misskey, an open source federated social media platform, has a vulnerability in the JSON-LD signature validation and compaction process that allows spoofed activities to be accepted as valid.
- CVE-2026-48115Medium
Misskey versions from 2024.5.0 up to 2026.5.4 (pre-patch) contain a vulnerability in the Server Announcements API where insufficient permission checks allow attackers to access limited portions of data they normally couldn't view. This vulnerability occurs whether or not federation is enabled.
- CVE-2026-47746High
Misskey, an open-source federated social media platform, versions 12.37.0 through 2026.5.4, is vulnerable to timing attacks during JSON-LD signature validation and compaction. Lack of shared JSON-LD parsing context between signature verification and processing leads to a TOCTOU flaw, allowing an attacker to have fraudulent activities accepted as valid. Fixed in version 2026.5.4.
- CVE-2026-46714Medium
Misskey versions from 8.63.0 up to 2026.5.4 (pre-patch) contain a vulnerability that can cause the web client to slow down or crash when it applies a malformed theme.
- CVE-2026-46712Low
Misskey versions 2025.3.2 up to (but not including) 2026.5.4 have a missing permission check that allows access to certain Direct Messages data regardless of account permissions. Notes with 'specified' visibility are not affected. Fixed in version 2026.5.4.
- CVE-2026-57574High
Misskey prior to version 2026.6.0 contains a vulnerability in TOTP authentication where insufficient validation of used tokens allows reuse of a single-use code within its valid time step. An attacker who obtains both credentials and a TOTP code can reuse it for unauthorized actions, potentially leading to account takeover.
Original NVD description (English source)
Misskey is an open source, federated social media platform. Prior to 2026.6.0, Misskey contains a Server-Side Request Forgery (SSRF) vulnerability in URL preview functionality in UrlPreviewService. Due to missing network restrictions before establishing outbound connections, a remote attacker can cause the Misskey server to initiate HTTP requests to loopback, private, or link-local services. Because IP address validation takes place after the request has been sent and the process is subsequently rejected, no sensitive internal data is believed to be transmitted back or exposed to the attacker. This issue is fixed in version 2026.6.0.