How severe is CVE-2026-21855?

CVE-2026-21855 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-21855 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21855?

CVE-2026-21855 affects Tarkov Tarkov Data Manager. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-21855?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-21855 have an EU (EUVD) identifier?

Yes. CVE-2026-21855 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1400.

When was CVE-2026-21855 published?

CVE-2026-21855 was published on 2026-01-07 and last updated on 2026-06-17.

CVE-2026-21855

CVE-2026-21855 is a critical-severity vulnerability in Tarkov Tarkov Data Manager with a CVSS 3.x base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Critical (CVSS 3.x base score 9.3)
EPSS exploit prediction: 0% (10th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-1400
Weakness: CWE-79
Affected product: Tarkov Tarkov Data Manager
Published: 2026-01-07
Last modified: 2026-06-17

Description

The Tarkov Data Manager is a tool to manage the Tarkov item data. Prior to 02 January 2025, a reflected Cross Site Scripting (XSS) vulnerability in the toast notification system allows any attacker to execute arbitrary JavaScript in the context of a victim's browser session by crafting a malicious URL. A series of fix commits on 02 January 2025 fixed this and other vulnerabilities.

Frequently asked questions

What is CVE-2026-21855?: The Tarkov Data Manager is a tool to manage the Tarkov item data. Prior to 02 January 2025, a reflected Cross Site Scripting (XSS) vulnerability in the toast notification system allows any attacker to execute arbitrary JavaScript in the context of a victim's browser session by crafting a malicious URL. A series of fix commits on 02 January 2025 fixed this and other vulnerabilities.
How severe is CVE-2026-21855?: CVE-2026-21855 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-21855 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21855?: CVE-2026-21855 affects Tarkov Tarkov Data Manager. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-21855?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-21855 have an EU (EUVD) identifier?: Yes. CVE-2026-21855 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1400.
When was CVE-2026-21855 published?: CVE-2026-21855 was published on 2026-01-07 and last updated on 2026-06-17.

References

https://github.com/the-hideout/tarkov-data-manager/security/advisories/GHSA-9c23-rrg9-jc89

Affected products (1)

cpe:2.3:a:tarkov:tarkov_data_manager:*:*:*:*:*:*:*:*

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