Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-56122 – Arbitrary File Read via Path Traversal – Winstone Servlet Container ≤ 0.9.10

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-56122 is a path traversal vulnerability (CWE-22) affecting Winstone Servlet Container through version 0.9.10, the final release of the unmaintained standalone project by rickknowles. An unauthenticated remote attacker can read arbitrary files on the host filesystem by sending a single crafted HTTP GET request containing unsanitized dot-dot-slash sequences, with no authentication or user interaction required. The vulnerability carries a CVSS v3.1 score of 7.5 (HIGH) and a CVSS v4.0 score of 8.7 (HIGH).

Technical details

  • Root cause: The static file serving mechanism in Winstone does not sanitize dot-dot-slash (../) sequences in HTTP request paths, allowing an attacker to traverse outside the configured webroot directory and reach arbitrary locations on the filesystem.
  • Trigger conditions: A single HTTP GET request with a traversal-prefixed path is sufficient — for example, a request to http://<host>:<port>/../../../../../../etc/passwd using the --path-as-is flag (to prevent client-side path normalization) directly retrieves the targeted file.
  • Attack vector: Network-accessible with no authentication (PR:NONE) and no user interaction (UI:NONE) required; exploitable by any unauthenticated internet user with access to the service port.
  • Impact: Unauthenticated arbitrary file read. An attacker can retrieve any file readable by the servlet engine process — including /etc/passwd, application configuration files, and credentials. When Winstone runs with elevated privileges, the scope extends to highly sensitive files such as /etc/shadow and private key material.

Affected software

  • Winstone Servlet Container, all versions through 0.9.10 (vendor: rickknowles)

Severity

  • CVSS v3.1 Base Score: 7.5 HIGH
  • Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Mitigation and recommended actions

  • No patch is available. The Winstone standalone project has not received updates since its last release (version 0.9.10, May 2013) and is no longer maintained by its original author.
  • Immediate: Restrict or block external network access to any internet-exposed Winstone instance using firewall rules or network segmentation to eliminate remote exploitability.
  • Operational hardening: Ensure the Winstone process runs under the least-privileged OS user account possible, limiting the files an attacker can reach via arbitrary file read.
  • Longer-term: Migrate to an actively maintained and supported Java servlet container; continued reliance on unsupported software carries ongoing unpatched risk.

IONIX Status

The IONIX research team is tracking ongoing exploitation attempts and recommends immediate patching. Potentially affected assets are outlined in this post.

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge