CVE-2026-21855Public exploitNetwork attack vector

Browser script execution via unescaped toast input

Published Jan 7, 2026 · Updated Jan 7, 2026

Reflected XSS in The Hideout Tarkov Data Manager 2.0.0 and earlier allows remote attackers to execute JavaScript via a malicious URL. The decodeToast() function decodes the toast query parameter from hex, and getFooter() interpolates the result into a JavaScript string without escaping or sanitization. A victim must follow the crafted link; the resulting same-origin script can read authenticated page data and issue requests in that browser session.

CVSS severity9.3
Critical
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in The Hideout Tarkov Data Manager 2.0.0 and earlier allows remote attackers to execute JavaScript via a malicious URL. The decodeToast() function decodes the toast query parameter from hex, and getFooter() interpolates the result into a JavaScript string without escaping or sanitization. A victim must follow the crafted link; the resulting same-origin script can read authenticated page data and issue requests in that browser session.

The record

CVE
CVE-2026-21855
Published
Jan 7, 2026
Updated
Jan 7, 2026
Vendor
The Hideout
Product
Tarkov Data Manager
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 7, 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=<= 2.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Hideout · Tarkov Data Managerversion=<= 2.0.0

Published CVSS scores

9.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/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.

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')
T1204.001User Execution: Malicious Link

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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