CVE-2026-102991

NameCVE-2026-102991
DescriptionMako is a template library written in Python. Prior to 1.4.2, on Windows, TemplateLookup.get_template() in mako/lookup.py resolves template URIs with posixpath, while Template.__init__() in mako/template.py validates them with os.path, which uses ntpath. A URI beginning with a drive designator causes ntpath to absorb the traversal segments before the leading dot-dot check, while posixpath resolution can escape the configured template directory. An application that passes attacker-controlled template names or include paths can disclose process-readable files on the same volume, and a targeted file containing Mako template syntax may also be parsed and executed as a template. Raw URL paths are generally normalized before reaching this form, but query strings, form or JSON bodies, route parameters, and dynamic include expressions can preserve it. This issue is fixed in version 1.4.2.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
mako (PTS)bookworm1.2.4+ds-1fixed
trixie1.3.9-1fixed
forky, sid1.3.10-3fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
makosource(unstable)(not affected)

Notes

- mako <not-affected> (Only affects Mako on Windows)
https://github.com/sqlalchemy/mako/security/advisories/GHSA-5639-2j2p-m4mx
https://github.com/sqlalchemy/mako/issues/441
Fxied by: https://github.com/sqlalchemy/mako/commit/000ed85e4e48771eff460bf4fc721fb43de80e08 (rel_1_4_2)

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