CVE-2025-27516

CVE-2025-27516 is a critical vulnerability in Jinja, an extensible templating engine, affecting versions prior to 3.1.6. It allows an attacker to execute arbitrary Python code by exploiting an oversight in how the sandboxed environment interacts with the |attr filter, specifically bypassing the sandbox's protection against str.format. This vulnerability impacts applications using untrusted templates and is present in Debian Linux and PalletsProjects Jinja. The vulnerability carries a high CVSS score of 8.8, indicating a severe risk. It has a local attack vector (AV:L) with low attack complexity (AC:L) and requires low privileges (PR:L), leading to high confidentiality, integrity, and availability impacts (C:H/I:H/A:H). The potential impact is significant, as successful exploitation grants arbitrary code execution. Currently, there is no evidence of active exploitation, and no public exploit code (Metasploit, Nuclei, ExploitDB) is available. While there is minimal community discussion, a GitHub fix related to this CVE has been noted. The vulnerability is fixed in Jinja version 3.1.6.