CVE-2026-119716
pybars3 through 0.9.7 and pybars4 through 0.9.13 contain a code injection vulnerability in pybars/_compiler.py that allows template authors to execute Python code via unescaped bracketed path segments.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
pybars3 through 0.9.7 and pybars4 through 0.9.13 contain a code injection vulnerability in pybars/_compiler.py that allows template authors to execute Python code via unescaped bracketed path segments. Attackers can supply Handlebars templates with crafted segments in helper or block arguments to break out of string literals and execute Python in the application process.
- CVSS 4.0
- 9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.46% probability · 40th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-94
- Source
- disclosure@vulncheck.com
EPSS moved from 0.4% on 31 October 2026 to 0.5% on 3 November 2026.
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://github.com/wbond/pybars3
- https://github.com/wbond/pybars3/blob/0.9.7/pybars/_compiler.py#L159-L160
- https://github.com/wbond/pybars3/issues/88
- https://www.vulncheck.com/advisories/pybars3-through-0.9.7-code-injection-via-bracketed-path-segments
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.