Jinja2 sandbox escape via string formatting
In Pallets Jinja before 2.10.1, str.format_map allows a sandbox escape.
The sandbox is used to restrict what code can be evaluated when rendering untrusted, user-provided templates. Due to the way string formatting works in Python, the str.format_map method could be used to escape the sandbox.
This issue was previously addressed for the str.format method in Jinja 2.8.1, which discusses the issue in detail. However, the less-common str.format_map method was overlooked. This release applies the same sandboxing to both methods.
If you cannot upgrade Jinja, you can override the is_safe_attribute method on the sandbox and explicitly disallow the format_map method on string objects.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | jinja2 | < 2.10.1 | 2.10.1 |
References
- https://palletsprojects.com/blog/jinja-2-10-1-released
- https://lists.apache.org/thread.html/b2380d147b508bbcb90d2cad443c159e63e12555966ab4f320ee22da@%3Ccommits.airflow.apache.org%3E
- https://lists.apache.org/thread.html/46c055e173b52d599c648a98199972dbd6a89d2b4c4647b0500f2284@%3Cdevnull.infra.apache.org%3E
- https://lists.apache.org/thread.html/f0c4a03418bcfe70c539c5dbaf99c04c98da13bfa1d3266f08564316@%3Ccommits.airflow.apache.org%3E
- https://lists.apache.org/thread.html/7f39f01392d320dfb48e4901db68daeece62fd60ef20955966739993@%3Ccommits.airflow.apache.org%3E
- https://lists.apache.org/thread.html/57673a78c4d5c870d3f21465c7e2946b9f8285c7c57e54c2ae552f02@%3Ccommits.airflow.apache.org%3E
- https://lists.apache.org/thread.html/320441dccbd9a545320f5f07306d711d4bbd31ba43dc9eebcfc602df@%3Cdevnull.infra.apache.org%3E
- https://lists.apache.org/thread.html/2b52b9c8b9d6366a4f1b407a8bde6af28d9fc73fdb3b37695fd0d9ac@%3Cdevnull.infra.apache.org%3E
- https://lists.apache.org/thread.html/09fc842ff444cd43d9d4c510756fec625ef8eb1175f14fd21de2605f@%3Cdevnull.infra.apache.org%3E
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QCDYIS254EJMBNWOG4S5QY6AOTOR4TZU/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DSW3QZMFVVR7YE3UT4YRQA272TYAL5AF/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TS7IVZAJBWOHNRDMFJDIZVFCMRP6YIUQ/
- https://access.redhat.com/errata/RHSA-2019:1152
- http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00030.html
- https://access.redhat.com/errata/RHSA-2019:1237
- https://access.redhat.com/errata/RHSA-2019:1329
- https://usn.ubuntu.com/4011-1/
- https://usn.ubuntu.com/4011-2/
- http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00064.html
- https://github.com/advisories/GHSA-462w-v97r-4m45
- https://nvd.nist.gov/vuln/detail/CVE-2019-10906
- https://usn.ubuntu.com/4011-2
- https://usn.ubuntu.com/4011-1
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TS7IVZAJBWOHNRDMFJDIZVFCMRP6YIUQ
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QCDYIS254EJMBNWOG4S5QY6AOTOR4TZU
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DSW3QZMFVVR7YE3UT4YRQA272TYAL5AF
- https://github.com/pypa/advisory-database/tree/main/vulns/jinja2/PYSEC-2019-217.yaml
- https://github.com/pallets/jinja
- CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N- Weakness (CWE)
CWE-693- Platform
- Python (PyPI)
- Package
jinja2- Disclosed
- 07.04.2019
- Updated
- 11.10.2026 11:20
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2019-217 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-462w-v97r-4m45 - CC BY 4.0
Vulnerability history: jinja2
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 11
- First → latest
- 05.2014 06.2025
- Without a fix
- 1
- Exploited in attacks
- 0
Severity breakdown
- High 4
- Medium 7
Disclosures per year
- 2017: 0
- 2018: 0
- 2019: 2
- 2020: 0
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 4
- 2025: 2
- 2026: 0
earlier: 2
-
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