* fix(security): resolve symlinks in path validation to block out-of-root reads (#527)
validatePathWithinRoot was purely lexical (path.resolve + startsWith), so an
in-repo symlink whose logical path is inside the project root but whose real
target escapes it passed validation — and both content-serving read sinks
(codegraph_node includeCode, codegraph_explore source) then readFileSync'd it,
leaking out-of-root file contents (e.g. ~/.ssh, /etc) to the agent.
Add a realpath layer: after the lexical check, resolve symlinks on both the
candidate path and the root and re-compare, rejecting anything whose real path
escapes the root. An in-root symlink is still allowed (no over-blocking).
Comparison is case-insensitive on Windows (NTFS + realpath casing). Not-yet-
existing paths (ENOENT) fall back to the lexical result so about-to-be-written
files still validate; other resolution errors reject.
Removes the dead, never-called isPathWithinRoot / isPathWithinRootReal helpers
(the latter a footgun — it returned true on realpath failure). Adds RED->GREEN
tests: in->out file/dir symlinks rejected, in->in allowed, ../ rejected, ENOENT
allowed, plus an end-to-end test proving getCode no longer serves an out-of-root
file reached through a dir symlink.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* docs(changelog): note the #527 symlink path-escape fix
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
## Summary
Completes the explore-overhaul arc: `codegraph_explore` becomes the single primary tool an agent reaches for, and its coverage + output shape are tuned so flow/architecture questions resolve with near-zero Read/Grep.
### What changed
- **explore is the sole primary tool** — removed `codegraph_context` (the fuzzy-input Read-trigger) and `codegraph_trace` (under-picked by agents); explore already surfaces the call flow among the symbols you name. A plain natural-language question now works as the query.
- **Store/handler coverage** — functions defined inside object literals (Zustand `create((set, get) => ({ … }))`, Redux/Pinia/MobX, exported handler/route maps) are indexed as real symbols, including calls through `useStore.getState().fn()` and destructured `const { fn } = useStore.getState()`. A general AST rule, not a per-lib hack.
- **Overload disambiguation** — explore leads with the *right* definition when a method name is overloaded across types (a PascalCase type token in the query biases to that type's own def); `codegraph_node` returns *every* overload's body in one call, with an optional `file`/`line` selector to pin one.
- **Method-atomic render** — explore never returns half a method; at the size budget it drops whole methods/files (and lists what it dropped) instead of truncating a body mid-method.
- **Native-read-shaped output** — per-call output is capped to ~24K with a 25K hard ceiling and concentrated into ~150–250-line flow windows, mirroring how the agent natively reads; repo size scales the *call* budget, not the per-call size (a larger response just gets externalized to a file the host Reads back).
- **Blast radius** folded into explore (dependents + covering tests, locations only).
### Benchmark (refreshed on this build)
Re-validated the 7-repo A/B on 2026-06-02 (Opus 4.8, effort=high, median of 4). WITH arm re-measured on this build, WITHOUT reused:
**~16% cheaper · 47% fewer tokens · 22% faster · 58% fewer tool calls** — 0 file reads on 6 of 7 repos (Gin ~1).
The arc trades larger, cache-heavy explore responses for guaranteed near-zero reads, so cost/token margins soften vs the prior build (Excalidraw and Tokio land at cost break-even) while time and tool-calls stay clear wins everywhere — consistent with the project's stated optimization target (latency + tool-calls, not token cost).
### Validation
- Full suite green: **1112 passed, 2 skipped**.
- 28/28 plain WITH runs across the 7 README repos completed clean; reads median 0 on 6/7.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Validate projectPath in getCodeGraph so MCP clients can't open a codegraph in a
sensitive system directory. Guarded with existsSync so nested/not-yet-created
sub-paths still resolve up to the default project (preserves issue #238). Adds
MCP-handler rejection tests (POSIX + Windows-gated); validated on a real
Windows 11 VM.
Closes#230
Drop the no-op try/catch around insertNode.run, and lowercase the Windows
SENSITIVE_PATHS entries so validateProjectPath's case-insensitive check
actually blocks c:\windows. Adds a validateProjectPath test (POSIX +
Windows-gated); the Windows-gated case was validated on a real Windows 11 VM.
Closes#327
Route handleContext's output through the shared truncateOutput cap
(MAX_OUTPUT_LENGTH) so codegraph_context can no longer blow past the context
budget — every sibling MCP tool already truncates; this was the one uncapped
output path.
Closes#296
Co-authored-by: Baijack-star <71923891+Baijack-star@users.noreply.github.com>
Remove .codegraph/config.json and the entire config surface. CodeGraph now
indexes every file whose extension maps to a supported language and respects
.gitignore everywhere — git repos via git itself, non-git projects via the
`ignore` library (root + nested .gitignore files, the same way git does).
- Remove CodeGraphConfig/DEFAULT_CONFIG, src/config.ts, and the public config
API (the `config` option on init, getConfig/updateConfig/getConfigPath).
- Derive the source-file allowlist from EXTENSION_MAP (isSourceFile); maxFileSize
is now a constant. Drop the .codegraphignore marker.
- Behavior change: committed, non-gitignored dirs (vendor/, a committed dist/)
are now indexed — .gitignore is the single source of truth.
Earlier inert fields (languages, frameworks, extractDocstrings, trackCallSites,
customPatterns) and their dead helpers are removed as part of this.
Resolves#283.
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
`markSessionConsulted` writes `${tmpdir()}/codegraph-consulted-${hash}` on
every `codegraph_context` call so external tooling can detect that an MCP
session has consulted CodeGraph. The old `writeFileSync` followed symlinks
unconditionally, so on a multi-user system any other local user could
pre-create that marker path as a symlink pointing at a victim-writable
file — the next codegraph context call would then overwrite the target's
contents with the ISO timestamp string (CWE-59).
The session-id hash gates predictability and makes opportunistic exploit
infeasible on its own, but tmpdir() is world-writable (mode 1777 on Linux)
and the proper pattern is to never follow links into a shared-prefix
tmpfile. Switch to `openSync` with O_NOFOLLOW + mode 0o600. ELOOP from a
planted symlink lands in the existing silent-fail catch — refuse to write
rather than touch an attacker-chosen target.
Detected by Aeon + manual review.
Severity: medium
CWE-59 (link following), CWE-732 (incorrect permission for critical resource)
Co-authored-by: aaronjmars <aaron@aeon.local>
- Add validateProjectPath() to reject sensitive system directories
- Add isPathWithinRoot/isPathWithinRootReal for symlink-aware path checks
- Replace hand-rolled glob-to-regex with picomatch to prevent ReDoS
- Add isSafeRegex() to reject custom patterns with nested quantifiers
- Replace FileLock with PID-tracking version that detects stale locks
- Add symlink detection in removeDirectory/listDirectoryContents
- Add subdirectory name validation in ensureSubdirectory
- Add atomicWriteFileSync and corrupted file backup in config-writer
- Add MCP input validation (validateString) for all tool handlers
- Fix CLAUDE.md section replacement to handle ### subsections correctly
Aditya RawatandGitHub
Leon.CandGitHub
Baijack-starandGitHub
Martin Oehlert