Vulnerability · Published May 12, 2026 · Assigned by GitHub_M

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

High 8.7

In plain English

A high-severity path traversal in mako from sqlalchemy. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High

Exploit odds (30 days)0.7%top 45.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	mako	1.3.12	GHSA-2h4p-vjrc-8xpq
PyPI	mako	1.3.12	PYSEC-2026-2617
Ubuntu:22.04:LTS	mako	no fix listed	UBUNTU-CVE-2026-44307
Ubuntu:24.04:LTS	mako	no fix listed	UBUNTU-CVE-2026-44307
Ubuntu:25.10	mako	no fix listed	UBUNTU-CVE-2026-44307
Ubuntu:26.04:LTS	mako	no fix listed	UBUNTU-CVE-2026-44307

Affected products (as reported)

Vendor	Product	Versions
sqlalchemy	mako	< 1.3.12

Weakness: CWE-22 · 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

References

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