Arbitrary file read via inconsistent slash stripping
Published Apr 23, 2026 · Updated Apr 23, 2026
Path traversal in SQLAlchemy Mako before 1.3.11 allows remote attackers to read process-accessible files through crafted template URIs. TemplateLookup.get_template() strips every leading slash before joining a URI to the template directory, while Template.init strips only one, letting double-slash traversal normalize to an absolute path that bypasses the parent-directory check. Exploitation requires an application to pass untrusted input directly to the API; HTTP servers that normalize double-slash prefixes block that route.
Summary
What happened
Path traversal in SQLAlchemy Mako before 1.3.11 allows remote attackers to read process-accessible files through crafted template URIs. TemplateLookup.get_template() strips every leading slash before joining a URI to the template directory, while Template.init strips only one, letting double-slash traversal normalize to an absolute path that bypasses the parent-directory check. Exploitation requires an application to pass untrusted input directly to the API; HTTP servers that normalize double-slash prefixes block that route.
The record
- CVE
- CVE-2026-41205
- Published
- Apr 23, 2026
- Updated
- Apr 23, 2026
- Vendor
- SQLAlchemy
- Product
- Mako
- Classifications
- CWE-22, T1005
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 23, 2026CVE publishedPublication date reported by the CVE source.
- Apr 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.3.11
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Double-slash TemplateLookup traversal exampleproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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