Ghost EUVD-2026-90684

Requires an authenticated Ghost staff account (PR:L) with access to insert or edit image cards in the editor; exploitation works against default configurations of affected versions (3.20.2 before 6.51.0) with no user interaction. The attacker must supply an attacker-controlled or internal URL to an image card and trigger the image dimension refetch. Real impact is sharply amplified when Ghost is cloud-hosted with a reachable link-local metadata service (169.254.169.254) or sensitive internal network services; it is limited to internal reconnaissance when no such internal resources are reachable. The staff-authentication gate and the absence of unauthenticated access are the primary limiting factors.

This is a moderate, authenticated SSRF in Ghost (CWE-918), and the signals converge on medium rather than high priority. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N) scores 5.3 and confirms network reach with low attack complexity but requires PR:L - an authenticated staff user - which meaningfully gates exploitation. Exploitation status: no public exploit identified at time of analysis (no POC, no CISA KEV listing, no EPSS provided), so there is no evidence of active or automated exploitation. The real risk driver is not the base score but the deployment context: in cloud-hosted Ghost instances, SSRF to internal endpoints and link-local metadata services (e.g. 169.254.169.254) can expose IAM credentials or internal-only services, which can escalate impact well beyond the modest VC:L/VI:L rating. Conversely, in self-hosted environments without a metadata service or sensitive internal network, the practical impact is limited to internal reconnaissance. No signals are strongly conflicting; the main caveat is that CVSS VC:L/VI:L may understate real-world consequences when a reachable metadata service exists.

An authenticated staff user in a cloud-hosted Ghost instance inserts an image card and points its URL at an internal endpoint or the cloud metadata service (http://169.254.169.254/latest/meta-data/), then triggers the image dimension refetch. The Ghost server performs the outbound request on the attacker's behalf and returns or acts on data from resources unreachable from the public internet. No public exploit code is identified at this time, but the attack is low-complexity once staff access is held.