CVE-2026-45136 — claude-code-cache-fix
Fix: cnighswonger/claude-code-cache-fix#110CVE-2026-45136 is a OS Command Injection vulnerability in claude-code-cache-fix. A fix is available for claude-code-cache-fix — see the affected versions and patch details below.
claude-code-cache-fix: Local code execution via Python triple-quote injection in tools/quota-statusline.sh
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-45136.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
claude-code-cache-fixnpmDescription
Summary
tools/quota-statusline.sh (introduced in v3.5.0) interpolates Claude Code's hook stdin payload directly into a Python triple-quoted string literal. A ''' byte sequence in any user-controlled field of the payload closes the literal early and lets following bytes execute as Python in the user's Claude Code process.
Affected versions
- v3.5.0
- v3.5.1
Patched versions
- v3.5.2
Affected configurations
Users who wired tools/quota-statusline.sh into Claude Code's statusLine configuration. The v3.5.0 README explicitly recommends this setup, so most users on v3.5.0/v3.5.1 with the recommended setup are affected.
Attack chain
Claude Code's statusline hook payload reflects user-controlled paths (cwd, workspace.current_dir, workspace.project_dir, transcript_path). Apostrophes are legal in POSIX filesystem paths.
- A hostile directory name containing
'''+payload+'''lands on disk via any normal vector —git clone, archive extraction, npm package, downloaded zip, etc. - The victim has the recommended
tools/quota-statusline.shwired into their CCstatusLineconfig. - The victim
cds anywhere a hostile path is reachable. - CC fires the statusline hook on every redraw. The Python literal closes early. The injected bytes execute as Python in the user's process.
Severity
Local code execution at user privilege. Persistent re-fire on every statusline redraw. No user interaction beyond cd-ing into the hostile path. The user's shell, CC session, files, SSH keys, and any locally-accessible credentials are reachable from the executed code.
Vulnerable pattern
input=$(cat)
result=$(python3 -c "
stdin_data = json.loads('''$input''') if '''$input''' else {}
")
Fix
Capture stdin in bash, export to env, and pipe the Python source through a single-quoted heredoc (<<'PYEOF'). Single-quoting disables ALL bash interpolation inside the body. Python reads the JSON via os.environ.get('CC_INPUT'), where the bytes are inert at every layer.
CC_INPUT=$(cat)
export CC_INPUT
python3 <<'PYEOF' 2>/dev/null
import os, json
try:
cc_input = json.loads(os.environ.get('CC_INPUT') or '{}')
except Exception:
cc_input = {}
# ...
PYEOF
Workarounds
Until upgrading to v3.5.2:
- Disable the statusline by removing the
statusLineentry from~/.claude/settings.json, or - Replace
tools/quota-statusline.shwith a script that does NOT pass stdin throughpython3 -c "..."(a heredoc + env var rewrite is safe)
Credit
Reported by Jakob Linke (@schuay) via GitHub issue #108.
Timeline
- 2026-05-07 — reported (#108)
- 2026-05-07 — confirmed, fix implemented (#110)
- 2026-05-07 — v3.5.2 published
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | claude-code-cache-fix | ≥ 3.5.0&&< 3.5.2 | 3.5.2npm install claude-code-cache-fix@3.5.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for claude-code-cache-fix, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update claude-code-cache-fix to 3.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45136 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-45136 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-45136. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-45136 in your dependencies?
O3 Security finds CVE-2026-45136 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.