CVE-2026-104851 fsspec - Template Injection

fsspec 0.9.0 to 2026.6.0 contains a template injection caused by unrestricted jinja2.Template rendering in ReferenceFileSystem, letting attackers execute arbitrary Python code when opening crafted reference JSON documents, exploit requires attacker-controlled document input.

CVSS base score 8.8 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.32% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Template Injection
Impact
Remote Code Execution
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
2 October 2026
Updated
15 October 2026
Weakness
CWE-94

Vendor fix

Update to version 2026.6.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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