elixir-lang Elixir 1.20.0-rc.4/1.20.4 Partitioned Dependency Compilation deps.partition.ex Mix.Tasks.Deps.Partition.server temp file

Summaryinfo

A vulnerability has been found in elixir-lang Elixir 1.20.0-rc.4/1.20.4 and classified as problematic. Affected is the function Mix.Tasks.Deps.Partition.server of the file lib/mix/lib/mix/tasks/deps.partition.ex of the component Partitioned Dependency Compilation. This manipulation causes temp file. This vulnerability is tracked as CVE-2026-97209. The attack is restricted to local execution. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic was found in elixir-lang Elixir 1.20.0-rc.4/1.20.4. Affected by this vulnerability is the function Mix.Tasks.Deps.Partition.server of the file lib/mix/lib/mix/tasks/deps.partition.ex of the component Partitioned Dependency Compilation. The manipulation with an unknown input leads to a temp file vulnerability. The CWE definition for the vulnerability is CWE-377. Creating and using insecure temporary files can leave application and system data vulnerable to attack. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Insecure Temporary File vulnerability in Mix deps.partition in Elixir allows a local user to execute code as another user via a swapped partition config file. Partitioned dependency compilation passes the project configuration to each partition VM through a file in a fixed-name directory under the shared system temporary directory, and the partition trusts what it reads back. Another local user on the same host can exploit this during a mix deps.compile run that uses partitioned compilation. Mix.Tasks.Deps.Partition.server/4 in lib/mix/lib/mix/tasks/deps.partition.ex creates the directory with File.mkdir_p/1, which accepts an existing directory without checking its owner, so a user who created it first can replace the file before client/0 reads it. This issue affects mix: from 1.20.0-rc.4 before 1.20.5.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-97209 since 10/14/2026. The exploitation appears to be easy. An attack has to be approached locally. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

Upgrading to version 1.20.5 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• elixir-lang

Name

• Elixir

Version

• 1.20.0-rc.4
• 1.20.4

Website

• Product: https://github.com/elixir-lang/elixir/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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