Strands Agents: Default FileSessionManager storage is world-readable on shared systems

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.7 · CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

There is a local confidentiality issue in the default `FileSessionManager` storage behavior. By default it writes session data under `/tmp/strands/sessions` and relies on the process umask for directory and file permissions. On systems using the common `umask 022`, the session directories are `0755` and JSON files are `0644`, so other local users can read persisted agent session data. This matters on shared developer machines, CI hosts, notebooks, jump boxes, and multi-user GPU servers. Session storage is intended to persist conversation/history/state, so it can contain prompts, model output, tool inputs/outputs, intermediate state, and secrets that pass through the agent. Relevant code: - `strands-py/src/strands/session/file_session_manager.py:58`: default storage path is `os.path.join(tempfile.gettempdir(), "strands/sessions")`. - `strands-py/src/strands/session/file_session_manager.py:118`: creates parent directories without a private mode. -…

Published by the source

27 Oct 2026, 15:34 UTC

Last modified by the source

27 Oct 2026, 15:47 UTC

Source last checked

28 Oct 2026, 06:10 UTC

1. Revision 2 · amended · 28 Oct 2026

   Amended from osv record GHSA-763v-5pjm-fx36

2. Revision 1 · created · 27 Oct 2026

   Published from ghsa record GHSA-763v-5pjm-fx36

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# Patch Next advisory brief: GHSA-763v-5pjm-fx36

Advisory: Strands Agents: Default FileSessionManager storage is world-readable on shared systems
IDs: GHSA-763v-5pjm-fx36
Record: https://patchnext.com/advisories/ghsa-763v-5pjm-fx36 (revision 2, source checked 28 Oct 2026, 06:10 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: strands-agents 1.48.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI strands-agents: affected < 1.48.0; fixed in 1.48.0

## Suggested inspection (read-only)
- `python -m pip show strands-agents`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on strands-agents.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-763v-5pjm-fx36 (OSV record GHSA-763v-5pjm-fx36 lists affected ranges: PyPI strands-agents >=0 <1.48.0 (fixed))
- Verified: https://github.com/advisories/GHSA-763v-5pjm-fx36 (GitHub-reviewed advisory GHSA-763v-5pjm-fx36 lists affected ranges: PyPI strands-agents >=0 <1.48.0)

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