How severe is CVE-2021-43186?

CVE-2021-43186 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-43186 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43186?

CVE-2021-43186 affects Jetbrains Youtrack. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43186?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-43186 published?

CVE-2021-43186 was published on 2021-11-09 and last updated on 2026-06-17.

CVE-2021-43186

CVE-2021-43186 is a medium-severity vulnerability in Jetbrains Youtrack with a CVSS 3.x base score of 5.4. 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: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Jetbrains Youtrack
Published: 2021-11-09
Last modified: 2026-06-17

Description

JetBrains YouTrack before 2021.3.24402 is vulnerable to stored XSS.

Frequently asked questions

What is CVE-2021-43186?: JetBrains YouTrack before 2021.3.24402 is vulnerable to stored XSS.
How severe is CVE-2021-43186?: CVE-2021-43186 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-43186 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43186?: CVE-2021-43186 affects Jetbrains Youtrack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43186?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-43186 published?: CVE-2021-43186 was published on 2021-11-09 and last updated on 2026-06-17.

References

https://blog.jetbrains.com/blog/2021/11/08/jetbrains-security-bulletin-q3-2021/

Affected products (1)

cpe:2.3:a:jetbrains:youtrack:*:*:*:*:*:*:*:*

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CVE-2026-62422 — Critical (CVSS 10.0): In JetBrains YouTrack before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429…
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