In JetBrains YouTrack before 2026.2.19422 cSS injection was possible in Mermaid diagrams via configuration directives
- Exploited
- No known exploitation
- Fix
- Fixed in 2026.2.19422
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 2026.2.19422.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 7/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
JetBrains YouTrack, before the fixed release, allowed CSS injection through configuration directives in Mermaid diagrams. An attacker who has a low-privileged account can reach it over the network, but it requires a user to take an action, and the impact is limited to altering how content is displayed.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
In JetBrains YouTrack before 2026.2.19422 cSS injection was possible in Mermaid diagrams via configuration directives
cve.now Index
- Exploitation0/40No signal
- Exposure3/25Reachable over the network · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity3.5/10CVSS 3.5
- No patch0/5No signal
What would change the score
- Would score about 62 if added to CISA KEV
- Would score about 57 if CISA's SSVC rates exploitation active
- Would score about 26 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 2026.2.19422.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- JetBrains YouTrack
fixed in 2026.2.19422
Evidence 1
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123850
Is CVE-2026-123850 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-123850?
YouTrack: before 2026.2.19422.Source: cve.now feed data
How do I fix CVE-2026-123850?
Upgrade to a fixed version: 2026.2.19422.Source: cve.now feed data