VulnerabilityDeferred

CVE-2026-53950

Prior to 3.1.0, the ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server.

HIGH 7.5EPSS 0.35%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.35%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

@tryghost/activitypub is Ghost’s social/federation client app. Prior to 3.1.0, the ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server. This vulnerability is fixed in 3.1.0.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.35% probability · 29th percentile
CISA KEV: Not listed
Weakness: CWE-79
Source: security-advisories@github.com

References

https://github.com/TryGhost/Ghost/security/advisories/GHSA-xpp7-93x6-v29m

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.