Package vulnerability, severity high
strands-agents-tools environment tool secret masking bypass (CVE-2026-115415) exposes env variables
Published , updated
The environment tool in the Python package strands-agents-tools accepted a masking parameter from the LLM, so a crafted prompt in processed content could turn masking off. The tool would then return the agent host's environment variables in cleartext, including cloud credentials and API keys. Versions >= 0.1.0 and < 0.8.6 are affected; 0.8.6 fixes it.
What's affected
- strands-agents-tools (pypi)>=0.1.0 <0.8.6
What to do
- Upgrade strands-agents-tools to version 0.8.6 or later.
- Rotate any credentials that were present in the environment of agents that loaded the environment tool.
- If you cannot upgrade right away, remove the environment tool from your agents.
- Avoid running agents with long-lived cloud credentials or API keys in the process environment, and restrict outbound network access from the agent host to trusted endpoints.
- Make sure any forked or derivative code includes the fix.
Secrets to rotate if you were affected
Cloud credentials, AI API keys, Environment variables.
Check whether you were affected
Pharon tells teams automatically when this affects something they run. To check a machine, run this in Claude Code with the Pharon plugin, in the repository that uses it:
/pharon:check-incident strands-agents-tools-secret-masking-bypass-2026-10References
Notice strands-agents-tools-secret-masking-bypass-2026-10, signed with key feed-prod-2026-10 (Ed25519). The Pharon CLI verifies the signature before using a notice.