🛡️ CVE-2026-53950 — ghost

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-79 NVD
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

XSS in Ghost's ActivityPub client

Impact

The ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server.

Vulnerable Versions

This vulnerability is present in the @tryghost/activitypub package up to v3.0.8. All prior versions are also affected.

Patches

@tryghost/activitypub v3.1.0 contains a fix for this issue and is also automatically fetched by Ghost.

References

Ghost thanks Brad Geesaman, Ghost Security for disclosing this vulnerability responsibly.

For more information

If you have any questions or comments about this advisory, email Ghost at [[email protected]](mailto:[email protected]).

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

CVE-2026-53950 is classified as CWE-79: Cross-site Scripting (XSS). User-supplied data is written into a page without escaping, so attacker script runs in the browser of anyone who views it.

Affected software

CVE-2026-53950 is recorded against 3 packages.

  • @tryghost/activitypub
  • ghost
  • unknown

Timeline and source

Published on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Package)

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE CWE-79
Public Exploit ✅ No
Source NVD
Published 2026-08-04
Updated 2026-08-12
Modified 2026-08-04
Fix URL N/A

Affected Packages

Software From version Fixed in
@tryghost/activitypub
ghost
unknown

Site Security Check

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