# NousResearch/hermes-agent · Shell injection via newlines in session env snapshots

## Open now

- Nothing open on GitHub.

A bug allows newlines in chat metadata or environment variables to execute shell commands through session snapshots. Multiple fix attempts address sanitizing or filtering multiline content in the snapshot pipeline.

## TL;DR

- 7 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 1 merged PR(s), 5 PR(s) closed without merging.
- A fix was merged to main in PR #72355. Verify it addresses your case.
- **Recommended:** read PR #72355 (and any competing PRs below) before filing. Confirm the merged change covers your symptom.

## Maintainer resolution verdict

- Internal-tracker verdict over this cluster's issue members: `resolved` · deciding PR(s): `pr-72355`. This is distinct from the fix status above. Weigh it yourself.

## How this cluster was grouped

- Link evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
- Pairwise link density `0.29`: the share of member pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. `1.00` means every pair is linked.

## Closed / duplicate issues

- #71296: \[Bug\]: Newline in a Matrix room/display name runs shell commands on the gateway host

## Prior & competing PRs

- **#72355: fix(environments): stop multiline session env from becoming shell via snapshot (salvage of #71306 by @HexLab98)**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`; implication `superseded`
  - files: `tests/tools/test_snapshot_multiline_session_env_injection.py`, `tests/tools/test_snapshot_session_id_leak.py`, `tools/environments/base.py`
- **#71306: fix(environments): stop multiline session env from becoming shell via snapshot**. closed without merge
  - maintainer direction: category `merged_via`; implication `superseded`; refs `#72355`
- **#71356: fix(security): sanitize newlines in chat metadata to prevent shell injection via env snapshot**. closed without merge
  - maintainer direction: category `superseded_by_pr`; implication `superseded`; refs `#71306`, `#71296`, `#71309`
- **#71414: fix(terminal): filter multiline continuation lines in env snapshot (#71296)**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `9677495004ef9a3460d4b29748e916db600b1b1e`
- **#71464: fix(terminal): prevent session snapshot injection**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `6290cd0d5`, `#71296`
- **#71974: fix(tools): harden session-snapshot filter against multiline injection (#71296)**. closed without merge
  - maintainer direction: category `silent_close`; implication `active`

## Fix status

- Merged to main in PR #72355 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-07-27`.
- Subsystem: `environments`