CVE-2026-53950Public exploitNetwork attack vector

Cross-site scripting via federated post content

Published Jun 24, 2026 · Updated Jun 24, 2026

Cross-site scripting in Ghost ActivityPub before 3.1.0 allows remote attackers to execute JavaScript through a malicious federated post. Ghost has not published the rendering locus or input-handling error that permits JavaScript from remote post content to execute. The attacker must control a customized ActivityPub server and a user must interact with its shared post; the script then executes in the viewing client.

CVSS severity7.5
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Ghost ActivityPub before 3.1.0 allows remote attackers to execute JavaScript through a malicious federated post. Ghost has not published the rendering locus or input-handling error that permits JavaScript from remote post content to execute. The attacker must control a customized ActivityPub server and a user must interact with its shared post; the script then executes in the viewing client.

The record

CVE
CVE-2026-53950
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
Ghost Foundation
Product
Ghost
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ghost Foundation · Ghostversion=< 3.1.0

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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