CVE-2026-75510Public exploitNetwork attack vectorHinoki check available

Stored XSS via unvalidated notification redirect scheme

Published Sep 22, 2026 · Updated Sep 22, 2026

Stored XSS in Novu before 3.18.0 allows remote authenticated users to execute JavaScript when a recipient clicks an Inbox notification. The v1 CTA path stores redirect.url and target without scheme validation, and the Inbox renderer passes the value to window.open in the hosting origin. Exploitation requires workflow-authoring access or an environment API key, an in-app channel, and a Chromium recipient click; resulting script access can expose session data and perform authenticated actions.

CVSS severityUnavailable
Unscored
EPSS probability0.35%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored XSS in Novu before 3.18.0 allows remote authenticated users to execute JavaScript when a recipient clicks an Inbox notification. The v1 CTA path stores redirect.url and target without scheme validation, and the Inbox renderer passes the value to window.open in the hosting origin. Exploitation requires workflow-authoring access or an environment API key, an in-app channel, and a Chromium recipient click; resulting script access can expose session data and perform authenticated actions.

The record

CVE
CVE-2026-75510
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
Novu
Product
Novu
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=< 3.18.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Novu · Novuversion=< 3.18.0

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
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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