CVE-2026-59791: In JetBrains YouTrack before 2026.2.17012 cSS injection via Mermaid diagram rendering was possible

Q: How do I fix CVE-2026-59791?

youtrack: upgrade to 2026.2.17012. Exact commands for each OS are on this page.

Q: Is CVE-2026-59791 being exploited?

CVE-2026-59791 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-59791 affect?

CVE-2026-59791 affects youtrack. Severity is low (CVSS 3.5). In JetBrains YouTrack before 2026.2.17012 cSS injection via Mermaid diagram rendering was possible

Q: How urgent is CVE-2026-59791?

Priority 15/100. No elevated risk signals yet.

Routine

LOW 3.5UPGRADE

CVE-2026-59791 is a low-severity flaw (CVSS 3.5) affecting youtrack. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In JetBrains YouTrack before 2026.2.17012 cSS injection via Mermaid diagram rendering was possible

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	3.5 (Low)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 87%)
CISA exploited list	No
Weakness	CWE-1021
Published	2026-07-10
Last modified	2026-10-24

Publisher (CNA): JetBrains s.r.o. · Vendor: jetbrains

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-10 15:16 UTCPublished CVE record published
2026-10-24 23:10 UTCUpdated Record last modified

jetbrains youtrack UPGRADE

Affected: < 2026.2.17012

Fixed in: 2026.2.17012

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy youtrack || rpm -q youtrack || youtrack --version

2. UPGRADE to 2026.2.17012 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade youtrack

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade youtrack

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-59791?

youtrack: upgrade to 2026.2.17012. Exact commands for each OS are on this page.

Is CVE-2026-59791 being exploited?

CVE-2026-59791 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-59791 affect?

CVE-2026-59791 affects youtrack. Severity is low (CVSS 3.5). In JetBrains YouTrack before 2026.2.17012 cSS injection via Mermaid diagram rendering was possible

How urgent is CVE-2026-59791?

Priority 15/100. No elevated risk signals yet.

Related CVEs

CVE-2026-62422 CRITICAL 10.0 UPGRADE In JetBrains YouTrack before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.
CVE-2026-75050 HIGH 7.1 UPGRADE In JetBrains YouTrack before 2026.1.13901, 2026.2.17950 doS attack was possible via crafted type parameters
CVE-2026-75048 HIGH 8.2 UPGRADE In JetBrains YouTrack before 2026.2.18068 stored XSS via the fenced code-block language label was possible
CVE-2026-75051 HIGH 8.1 UPGRADE In JetBrains YouTrack before 2026.2.17917 unauthorised project transfer between organisations was possible
CVE-2026-75049 MEDIUM 6.5 UPGRADE In JetBrains YouTrack before 2026.1.13903, 2026.2.17950 an authenticated user could read restricted articles

References

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