PYSEC-2026-2857

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/ouroboros-ai/PYSEC-2026-2857.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-2857
Aliases
Published
2026-07-13T15:19:15Z
Modified
2026-07-13T16:32:34Z
Severity
  • 8.6 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
ouroboros-ai Vulnerable to Remote Code Execution via Untrusted Project-Directory .env
Details

Impact

A Remote Code Execution (RCE) vulnerability was discovered in Ouroboros. If a user clones a malicious repository and runs Ouroboros commands within that directory, it can lead to arbitrary code execution and potential system takeover.

The vulnerability (CWE-426: Untrusted Search Path & CWE-15: External Control of System Setting) stems from Ouroboros loading the .env file from the current working directory. Prior to the patch, execution-affecting environment variables such as OUROBOROS_CLI_PATH, OPENCODE_CLI_PATH, and other backend selectors were accepted directly from this local .env. An attacker could include a malicious script in the repository and point the CLI path variable to it (e.g., OUROBOROS_CLI_PATH=./malicious_script.sh). When the user executes a command like ouroboros init or any command that instantiates the adapter, the malicious script is executed instead of the intended CLI.

Patches

The vulnerability has been patched in version 0.39.0 via PR #1078. The fix establishes a strict trust boundary by applying a denylist to project-local .env loading. It blocks execution-affecting environment variables (such as runtime selectors and CLI path overrides) from being loaded from the project directory. Explicit constructor overrides and trusted user-owned home configurations (~/.ouroboros/.env) remain fully functional.

Users are strongly advised to upgrade to version 0.39.0 or later.

Workarounds

If upgrading is not immediately possible, users must carefully inspect any .env file inside cloned repositories before running Ouroboros commands to ensure it does not contain unexpected OUROBOROS_*_CLI_PATH or OPENCODE_CLI_PATH overrides.

References

References

Affected packages

PyPI / ouroboros-ai

Package

Name
ouroboros-ai
View open source insights on deps.dev
Purl
pkg:pypi/ouroboros-ai

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.39.0

Affected versions

0.*
0.1.0a1
0.1.0
0.1.1
0.2.0
0.2.1
0.2.2
0.2.3
0.3.0
0.4.0
0.4.1
0.5.0
0.5.1
0.6.0
0.7.0
0.8.0
0.9.0
0.10.0
0.11.0
0.11.1
0.12.0
0.12.1
0.12.2
0.13.0
0.13.1
0.13.2
0.13.3
0.13.4
0.13.5
0.13.6
0.13.7
0.14.0
0.14.1
0.15.0
0.16.0
0.17.0
0.18.0
0.18.1
0.19.0
0.19.1
0.20.0
0.21.0
0.21.1
0.22.0
0.23.0
0.23.1
0.23.2
0.24.0
0.25.0
0.25.1
0.25.2
0.26.0b1
0.26.0b2
0.26.0b3
0.26.0b4
0.26.0b5
0.26.0b7
0.26.0
0.26.1
0.26.2
0.26.3
0.26.4
0.26.5
0.26.6
0.27.0
0.27.1
0.27.2
0.28.0
0.28.1
0.28.2
0.28.3
0.28.4
0.28.5
0.28.6
0.28.7
0.28.8
0.29.0
0.29.1
0.29.2
0.30.0
0.31.0
0.31.1
0.32.0
0.33.0
0.34.0
0.35.0
0.36.0
0.36.1.dev20
0.36.1.dev21
0.36.1.dev22
0.36.1.dev23
0.36.1.dev24
0.36.1.dev25
0.36.1.dev26
0.36.1.dev27
0.36.1.dev28
0.36.1.dev29
0.36.1.dev30
0.36.1.dev31
0.36.1.dev32
0.36.1.dev33
0.36.1.dev34
0.36.1.dev36
0.36.1.dev41
0.36.1.dev49
0.36.1.dev50
0.36.1.dev51
0.36.1.dev52
0.36.1.dev53
0.36.1.dev54
0.36.1.dev55
0.36.1.dev56
0.36.1.dev57
0.36.1.dev58
0.36.1.dev59
0.36.1.dev60
0.36.1.dev61
0.36.1.dev62
0.36.1.dev63
0.36.1.dev64
0.36.1.dev65
0.36.1.dev66
0.36.1.dev67
0.36.1.dev68
0.36.1.dev69
0.36.1.dev70
0.36.1.dev71
0.37.0
0.37.1.dev1
0.37.1.dev2
0.37.1.dev3
0.37.1.dev4
0.37.1.dev5
0.37.1.dev6
0.37.1.dev7
0.37.1.dev8
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0.37.1.dev18
0.37.1.dev19
0.37.1.dev20
0.37.1.dev21
0.37.1.dev22
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0.37.1.dev24
0.37.1.dev25
0.37.1.dev26
0.37.1.dev27
0.37.1.dev28
0.37.1.dev29
0.37.1.dev30
0.37.1.dev31
0.37.1.dev32
0.37.1.dev33
0.37.1.dev34
0.37.1.dev35
0.37.1.dev36
0.37.1.dev37
0.37.1.dev38
0.37.1.dev39
0.37.1.dev40
0.37.1.dev50
0.37.1.dev51
0.38.0
0.38.1.dev1
0.38.1.dev2
0.38.1.dev3
0.38.1.dev4
0.38.1
0.38.2.dev3
0.38.2
0.38.3.dev1
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0.38.3.dev31
0.38.3.dev33
0.38.3.dev41
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0.38.3.dev57
0.38.3.dev60
0.38.3.dev66
0.38.3.dev76
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0.38.3.dev148
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0.38.3.dev150
0.38.3.dev151
0.38.3.dev152
0.38.3.dev153
0.38.3.dev154
0.38.3.dev155
0.38.3.dev156
0.38.3.dev157
0.38.3.dev158
0.38.3.dev159
0.38.3.dev160
0.38.3.dev161
0.38.3.dev162
0.38.3.dev163
0.38.3.dev164
0.38.3.dev165
0.38.3.dev166

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/ouroboros-ai/PYSEC-2026-2857.yaml"