CVE-2026-119717

Description

pybars4 through 0.9.13 contains a code injection vulnerability in pybars/_compiler.py that allows attackers to execute Python code via unescaped bracketed path segments in Handlebars templates. Attackers can supply a template with a crafted segment in a helper or block argument to break out of the generated resolve() string literal and execute code in the application process.

References

• https://github.com/up9inc/pybars4
• https://github.com/up9inc/pybars4/blob/0.9.13/pybars/_compiler.py#L153-L154
• https://github.com/vladko312/advisories/blob/702e98db9642ece70d9e2150076d8014ffec2db3/pybars3.md
• https://www.vulncheck.com/advisories/pybars4-through-0.9.13-code-injection-via-bracketed-path-segments