Vulnerability · Published May 26, 2026 · Assigned by GitHub_M

CVE-2026-44209Banks: Critical Remote Code Execution (RCE) via Jinja2 SSTI

High 7.5

In plain English

A high-severity expression language injection in banks from masci. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 63.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Banks generates meaningful LLM prompts using a template language that makes sense. Prior to 2.4.2, banks uses jinja2.Environment() (unsandboxed) to render prompt templates. Applications that pass user-supplied strings as the template argument to Prompt() are vulnerable to Server-Side Template Injection (SSTI), which can lead to Remote Code Execution (RCE) on the host system. This vulnerability is fixed in 2.4.2.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	banks	2.4.2	GHSA-gphh-9q3h-jgpp
PyPI	banks	2.4.2	PYSEC-2026-2390

Affected products (as reported)

Vendor	Product	Versions
masci	banks	< 2.4.2

Weakness: CWE-1336, CWE-917 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References

https://github.com/masci/banks/security/advisories/GHSA-gphh-9q3h-jgpp x_refsource_CONFIRM
https://github.com/masci/banks/pull/74 x_refsource_MISC
https://access.redhat.com/security/cve/CVE-2026-44209 vdb-entry, x_refsource_REDHAT
RHBZ#2481713 issue-tracking, x_refsource_REDHAT
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44209.json x_sadp-csaf-vex