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TI-2026-76429 Aliases CVE-2026-111057GHSA-f8c7-rwf9-fmgm

Mercury: unauthenticated remote code execution via /api/terminals bypass

Priority HIGH 82CWE-185Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-284.

Summary

Mercury, a Python framework for sharing Jupyter notebooks as web applications, is affected from 3.0.0 before 3.2.4. A missing comma in BLOCKED_PATTERNS merges two regular expressions, so requests to /api/terminals bypass the anonymous endpoint blocklist (CWE-185). An unauthenticated remote attacker can reach the Jupyter Server terminal API, run operating-system shell commands and access data available to the Mercury process.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

Mercury is a Python framework for sharing Jupyter notebooks as web applications and dashboards. From 3.0.0 until 3.2.4, a missing comma in BLOCKED_PATTERNS concatenates the /lab and /api/terminals regular-expression literals. Requests to /api/terminals therefore bypass the anonymous endpoint blocklist and reach Jupyter Server's terminal API. An unauthenticated attacker can use the resulting interactive operating-system shell to execute commands and access data available to the Mercury process. This issue is fixed in version 3.2.4.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00698 53rd percentileScored 2026-11-07
Fix Fixed mercury (mljar): 3.2.4mercury (PyPI): 3.2.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
mljarmercury3.0.0 to before 3.2.43.2.4Patch availableCNA
—mercury (PyPI)3.0.0 to before 3.2.43.2.4Patch availableGHSA-f8c7-rwf9-fmgm
  • mercury Vendormljar Affected 3.0.0 to before 3.2.4 Fixed in 3.2.4 Patch available CNA
  • mercury (PyPI) Vendor— Affected 3.0.0 to before 3.2.4 Fixed in 3.2.4 Patch available GHSA-f8c7-rwf9-fmgm

Remediation

Upgrade the PyPI mercury package to version 3.2.4. The sources list no fixed version for the mljar vendor entry, but the PyPI entry lists 3.2.4 as fixed.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA mercury (mljar) Fixed in 3.2.4
  • Fix · GHSA-f8c7-rwf9-fmgm mercury (PyPI) Fixed in 3.2.4 Advisory →

Timeline

  1. 2026-10-19 Threatist record created from CVE-2026-111057
  2. 2026-10-19 Alias added: GHSA-f8c7-rwf9-fmgm
  3. 2026-10-19 Fix available: PyPI/[email protected] · GHSA-f8c7-rwf9-fmgm
  4. 2026-10-19 CVSS score added · GHSA-f8c7-rwf9-fmgm
  5. 2026-10-19 Weakness changed · GHSA-f8c7-rwf9-fmgm
  6. 2026-10-19 4 new references · GHSA-f8c7-rwf9-fmgm
  7. 2026-10-28 CISA SSVC decision points changed
  8. 2026-10-28 Priority changed: MEDIUM → HIGH
  9. 2026-10-29 EPSS moved to the 50th–90th percentile

References

Other 4

  • TI-2025-01287 Remote Code Execution in PlotAI CVSS 4.0CRITICAL 9.3
  • TI-2026-76430 Mercury lets anonymous clients execute arbitrary Python code CVSS 3.1CRITICAL 9.8
  • TI-2026-76431 Mercury mr.Markdown renders untrusted Markdown as unsanitized HTML (XSS) CVSS 3.1MEDIUM 6.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences