How severe is CVE-2026-86478?

CVE-2026-86478 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-86478 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-86478?

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.

When was CVE-2026-86478 published?

CVE-2026-86478 was published on 2026-09-07 and last updated on 2026-09-09.

CVE-2026-86478

CVE-2026-86478 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. 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-290.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-290
Published: 2026-09-07
Last modified: 2026-09-09

Description

In JetBrains YouTrack before 2025.3.161254, 2026.1.14042 improper authentication in YouTrack Helpdesk allowed unauthenticated account takeover via a self-asserted email address

Frequently asked questions

What is CVE-2026-86478?: In JetBrains YouTrack before 2025.3.161254, 2026.1.14042 improper authentication in YouTrack Helpdesk allowed unauthenticated account takeover via a self-asserted email address
How severe is CVE-2026-86478?: CVE-2026-86478 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-86478 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-86478?: 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.
When was CVE-2026-86478 published?: CVE-2026-86478 was published on 2026-09-07 and last updated on 2026-09-09.

References

https://www.jetbrains.com/privacy-security/issues-fixed/

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