Ghost: Member existence leak via magic link sign-in response

published 2026-06-24 4 mo ago modified 2026-10-25 14 d ago also BIT-ghost-2026-53947 , EUVD-2026-39022 , GHSA-chgm-3698-jm42

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits: 0; none known

Ghost is a Node.js content management system. From 5.18.0 until 6.21.1, a discrepancy in responses from the members signin endpoints made it possible for an unauthenticated attacker to determine whether a given email address belongs to a registered member of a Ghost site. This vulnerability is fixed in 6.21.1.

Patch / fix

fixed in 3 links 3

npm ghost 6.21.2
bitnami ghost 6.21.1
ghost ghost 6.21.1

github.com/TryGhost/Ghost@fb2bb63 commit
github.com/TryGhost/Ghost#26752 pull request
github.com/TryGhost/Ghost/releases/tag/v6.21.1 release

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 4 mo ago (2026-06-25)

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
GitHub	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
OSV	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	ghost	>=5.18.0, <6.21.2	6.21.2
bitnami	ghost	>=5.18.0, <6.21.1	6.21.1

Affected products

TryGhost Ghost

Classification

Weakness

CWE-204 Observable Response Discrepancy

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary