CVE-2026-60009: Eclipse Theia remote code execution (CVSS 8.8)

Description

In Eclipse Theia versions up to and including 1.73.1, the `@theia/filesystem` backend binds `POST /file-upload` in every filesystem-enabled deployment. The handler takes an attacker-supplied absolute path from the multipart `uri` field and calls `fs.move(tmp, target, { overwrite: true })` with no workspace confinement and no authentication. In browser (non-Electron) deployments the connection token is enforced only on WebSocket upgrades; the HTTP middleware in `@theia/core` re-issues the cookie and calls `next()` without rejecting tokenless HTTP requests. Because `multipart/form-data` is a CORS-safelisted request type, a cross-origin web page can trigger the write with no preflight and no credentials, resulting in an unauthenticated arbitrary file write outside the workspace to any absolute path the backend process can write. This can escalate to remote code execution, for example by overwriting a startup-executed file such as `~/.bashrc`. Electron mode uses a separate `ElectronSecurityToken` and is not affected via this path.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionRequired

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Eclipse Theia< 1.74.0

Remediation

Fixed in

Eclipse Theia≥ 1.74.0

Patch & vendor advisories

References

https://github.com/eclipse-theia/theia/security/advisories/GHSA-62f6-wcvg-54h3Broken Link
https://gitlab.eclipse.org/security/cve-assignment/-/work_items/177Vendor Advisory
https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/595ExploitMitigationVendor Advisory
https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/595ExploitMitigationVendor Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-60009 being actively exploited?

CVE-2026-60009 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.44%.

How severe is CVE-2026-60009?

CVE-2026-60009 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 0.44% probability of exploitation.

Which products are affected by CVE-2026-60009?

Affected products include Eclipse Theia.

How do I fix CVE-2026-60009?

Upgrade affected software to a fixed version, for example Eclipse Theia 1.74.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-60009 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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