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Fencer Intel
medium 4.4

CVE-2026-59831 json

GitHub CLI `gh codespace jupyter` could allow remote code execution when connecting to a malicious Codespace

published 4mo ago modified 3mo ago also EUVD-2026-42741

cvss
4.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

Summary

GitHub CLI (gh) is GitHub’s official command line tool. From 2.10.0 through 2.95.0, connecting to a malicious Codespace with gh codespace jupyter can allow command execution because the command opens a JupyterLab URL supplied by a process inside the Codespace without validating that it is a loopback HTTP or HTTPS address, allowing a crafted vscode:// or vscode-insiders:// URL to be handed to VS Code. This issue is fixed in version 2.96.0.

Patch / fix

  • github cli 2.96.0
  • gh openSUSE Leap 16.0 2.102.0-bp160.1.1
  • gh openSUSE Tumbleweed 2.102.0-1.1

opensuse advisories openSUSE-SU-2026:22134-1openSUSE-SU-2026:12163-1

  • gh Azure Linux 3.0 2.62.0-20

azure linux advisories AZL-92328

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2026-59831 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 4.4 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

  • cli cli

Classification

Weakness
  • CWE-829 Inclusion of Functionality from Untrusted Control Sphere

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.