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. 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.
Executive briefing
The source record describes: 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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Limited Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS vector:CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Weakness classification
CWE-94Affected products and versions
NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- https://github.com/up9inc/pybars4 VENDOR disclosure@vulncheck.com
- https://github.com/up9inc/pybars4/blob/0.9.13/pybars/_compiler.py#L153-L154 VENDOR disclosure@vulncheck.com
- https://github.com/vladko312/advisories/blob/702e98db9642ece70d9e2150076d8014ffec2db3/pybars3.md VENDOR disclosure@vulncheck.com
- https://github.com/wbond/pybars3 VENDOR disclosure@vulncheck.com
- https://github.com/wbond/pybars3/blob/0.9.7/pybars/_compiler.py#L159-L160 VENDOR disclosure@vulncheck.com
- https://github.com/wbond/pybars3/issues/88 VENDOR disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/pybars3-through-0.9.7-code-injection-via-bracketed-path-segments REFERENCE disclosure@vulncheck.com
- https://github.com/vladko312/advisories/blob/702e98db9642ece70d9e2150076d8014ffec2db3/pybars3.md VENDOR 134c704f-9b21-4f2e-91b3-4a467353bcc0
Information gaps & confidence notes
These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.
- NVD does not currently provide machine-readable vulnerable CPE product/version entries for this record.
Last enrichment: 2026-11-06T17:32:36+00:00 · Source last modified: 2026-11-06T17:17:19.403