CVE-2026-88963Network attack vectorHinoki check available

Script execution via unvalidated back-button redirect

Published Oct 16, 2026 · Updated Oct 16, 2026

DOM XSS in Themeum Tutor LMS 4.0.8 and earlier allows remote attackers to execute scripts via a crafted redirect_url parameter. The Topbar component's back-button handler accepts this attacker-controlled input without adequate validation. Exploitation requires a victim to access a page containing the payload, and execution occurs in the victim's browser rather than on the server.

CVSS severity6.1
Medium
EPSS probability0.19%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

DOM XSS in Themeum Tutor LMS 4.0.8 and earlier allows remote attackers to execute scripts via a crafted redirect_url parameter. The Topbar component's back-button handler accepts this attacker-controlled input without adequate validation. Exploitation requires a victim to access a page containing the payload, and execution occurs in the victim's browser rather than on the server.

The record

CVE
CVE-2026-88963
Published
Oct 16, 2026
Updated
Oct 16, 2026
Vendor
Themeum
Product
Tutor LMS
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 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=0 <=4.0.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Themeum · Tutor LMSversion=0 <=4.0.8

Published CVSS scores

6.1WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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