CVE-2026-47731
CRITICALCVE-2026-47731 is a critical-severity (CVSS 9.1) Path Traversal vulnerability in ait-core. O3 Security confirms whether CVE-2026-47731 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
NASA AMMOS Instrument Toolkit: Path traversal resulting in arbitrary file append (can be triggered over the network by unauthenticated attacker)
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.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-47731.
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.
How urgent is this, really
CVE-2026-47731 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 367,633 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
ait-core🐍ait-coreReal-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 AMMOS Instrument Toolkit (Formerly the Bespoke Links to Instruments for Surface and Space (BLISS)) is a Python-based software suite developed to handle Ground Data System (GDS), Electronic Ground Support Equipment (EGSE), commanding, telemetry uplink/downlink, and sequencing for instrument and CubeSat Missions. In versions prior to 2.6.1 and in version 3.1.0, the Binary Stream Capture (BSC) component exposes an unauthenticated HTTP API for dynamically creating packet capture "handlers." Because the code blindly trusts path‑related form fields, a remote client can bypass the configured log root and direct BSC to log to arbitrary filesystem paths (path traversal / directory escape), and append attacker‑controlled data to those files, using the privileges of theait-bsc process. There are two ways for a remote attacker to trigger this. First, if the attacker has access to the network where ait-bsc is deployed (a reason for that could be that the ports are publicly accessible), the payloads can be directly sent to the server to trigger the arbitrary file append. This type of attack is demonstrated in python_poc.py. Second, even if the attacker does not have direct access to the network because the software is running in a local network, it is possible to exploit this if a bad actor in that network opens an attacker-controlled website (which might be a website created by an attacker, or a third-party website compromised by the attacker). The browser javascript can automatically send the requests necessary to exploit this into the local network. This is even possible if the server is only accessible on localhost. This type of attack is demonstrated by attacker_tcp.py and test1.html (first launch the attacker TCP server, then start a webserver to host test1.html, for example using python3 -m http.server 7000, and open test1.html).This issue affects BSC (Binary Stream Capture) and usage of the ait-bsc server. This impacts AIT-Core versions before 3.1.1, from 2.x before 2.6.1. Users are recommended to upgrade to version 3.1.1 or 2.6.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | ait-core | ≥ 3.1.0&&< 3.1.1 | 3.1.1 |
| 🐍PyPI | ait-core | all versions | 2.6.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ait-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update ait-core to 3.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-47731 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 pinpoints whether CVE-2026-47731 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-47731. 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-2026-47731 in your dependencies?
O3 detects CVE-2026-47731 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.