CVE-2026-44209Public exploitNetwork attack vector

Remote code execution via unsandboxed Jinja2 templates

Published May 26, 2026 · Updated May 26, 2026

Server-side template injection in Banks before 2.4.2 allows remote attackers to execute arbitrary code through untrusted Prompt templates. The global environment in src/banks/env.py uses unsandboxed jinja2.Environment, allowing template expressions to traverse dunder attributes and reach Python builtins. Exploitation requires an application to pass attacker-controlled template text to Prompt(); successful rendering executes commands with the host process's privileges.

CVSS severity7.5
High
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side template injection in Banks before 2.4.2 allows remote attackers to execute arbitrary code through untrusted Prompt templates. The global environment in src/banks/env.py uses unsandboxed jinja2.Environment, allowing template expressions to traverse dunder attributes and reach Python builtins. Exploitation requires an application to pass attacker-controlled template text to Prompt(); successful rendering executes commands with the host process's privileges.

The record

CVE
CVE-2026-44209
Published
May 26, 2026
Updated
May 26, 2026
Vendor
Massimiliano Pippi
Product
Banks
Classifications
CWE-1336, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2026CVE publishedPublication date reported by the CVE source.
  2. May 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.4.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Massimiliano Pippi · Banksversion=< 2.4.2

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1336Improper Neutralization of Special Elements Used in a Template Engine
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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