CVE-2025-9556: Langchaingo

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

Langchaingo supports the use of jinja2 syntax when parsing prompts, which is in turn parsed using the gonja library v1.5.3. Gonja supports include and extends syntax to read files, which leads to a server side template injection vulnerability within langchaingo, allowing an attacker to insert a statement into a prompt to read the "etc/passwd" file.

Affected products

Published 2025-09-12. Last modified 2026-06-17.