In JetBrains Datalore before 2026.4 notebook code could execute commands in the sidecar container via the mount broker
- Exploited
- No known exploitation
- Fix
- Fixed in 2026.4
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 2026.4.
- 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? →
- 11/100 · 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
Summary
JetBrains Datalore before 2026.4 has a flaw that lets someone with a low-privilege account run commands in the sidecar container through the mount broker, using notebook code. The attack can be carried out remotely, but it is harder to pull off than a simple network bug, and it needs a logged-in account.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
In JetBrains Datalore before 2026.4 notebook code could execute commands in the sidecar container via the mount broker
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure3/25Reachable over the network · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 66 if added to CISA KEV
- Would score about 61 if CISA's SSVC rates exploitation active
- Would score about 30 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 2026.4.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- JetBrains Datalore
fixed in 2026.4
Evidence 1
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123281
Is CVE-2026-123281 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-2026-123281?
Datalore: before 2026.4.Source: cve.now feed data
How do I fix CVE-2026-123281?
Upgrade to a fixed version: 2026.4.Source: cve.now feed data