Information ExposureWeakness · CWE-200

CVE-2026-10055

HIGH · 8.5 CVSS v3.1 Published 2026-07-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
91/100
Remediation priority · Urgent
Remotely reachable Zero-click 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In Eclipse Theia since version 1.26.0, the backend /services/request-service RPC accepts an attacker-controlled URL from any client connected to the standard /services messaging endpoint, performs the HTTP request server-side, and returns the full response body to the caller. Because the destination URL is neither validated nor allowlisted, a remote attacker with access to the Theia service connection can issue server-side HTTP requests to localhost or other backend-reachable hosts and read their responses, exposing internal administrative endpoints, cloud instance metadata services, and other resources that are intentionally outside the browser network boundary. The vulnerability affects deployments where the Theia service connection is reachable by untrusted users (for example, multi-tenant or publicly-reachable Theia deployments).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Eclipse Theia versions 1.26.0+ contain an SSRF vulnerability in the backend /services/request-service RPC. The endpoint accepts attacker-controlled URLs from any client connected to the /services messaging endpoint, performs HTTP requests server-side without URL validation, and returns full response bodies. This allows remote attackers with service connection access to target internal services, cloud metadata endpoints, and localhost resources.

MitigationImplement strict URL allowlisting or validation for the request-service to restrict destinations to trusted external resources only, and consider network segmentation to limit backend access to sensitive internal services.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Theia version
    Locate the installed Theia version (typically in package.json, about dialog, or IDE metadata). Compare it to the affected range: version 1.26.0 or higher.
    Affected if Installed version is 1.26.0 or higher
  2. Identify request-service exposure
    Inspect the backend service configuration to determine if the /services/request-service RPC endpoint is enabled and accessible. This is typically configured in the backend service definitions or extension setup.
    Affected if The request-service RPC endpoint is exposed and reachable by clients
  3. Verify client connectivity to /services
    Determine whether untrusted or public clients can connect to the /services messaging endpoint, as the CVE states the attacker needs service connection access.
    Affected if Untrusted or anonymous clients can connect to the /services messaging endpoint
  4. Check for URL validation
    Review any existing URL validation, allowlisting, or restriction configurations around the request-service to see if it validates or restricts destination URLs before making requests.
    Affected if No URL validation or allowlisting mechanism is configured for the request-service

A user is affected if they run Theia 1.26.0+ with the request-service RPC endpoint enabled and accessible to untrusted clients without any URL validation in place.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement strict URL allowlisting or validation for the request-service to restrict destinations to trusted external resources only, and consider network segmentation to limit backend access to sensitive internal services.

Have this fixed Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,280
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-10055 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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