Cyber Resilience

CVE-2026-46580

High

Published: 18 June 2026

Published
18 June 2026
Modified
22 June 2026
KEV Added
Patch
CVSS Score v4 8.4 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0027 19.0th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-46580 is a high-severity Inclusion of Functionality from Untrusted Control Sphere (CWE-829) vulnerability in Eclipse Theia. Its CVSS base score is 8.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Compromise Software Supply Chain (T1195.002); ranked at the 19.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

In Eclipse Theia versions prior to 1.71.0, files matching the pattern .prompts/*.prompttemplate in a workspace were automatically loaded and could override or extend the AI agent's system prompts. An attacker could craft a malicious repository containing prompt template files that,…

more

when the workspace was opened in Theia, replaced the AI's system instructions with attacker-controlled content (indirect prompt injection). Combined with other AI chat features available in untrusted workspaces, this enabled attack chains leading to data exfiltration via Markdown image rendering or arbitrary command execution via task definitions.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1195.002 Compromise Software Supply Chain Initial Access
Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise.
Why these techniques?

Vulnerability enables loading of attacker-controlled files from a malicious workspace/repository, directly facilitating compromise of the software supply chain via poisoned development artifacts.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Affected Assets

eclipse
theia
≤ 1.71.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-829

Limiting P2P file sharing technology reduces inclusion of functionality or resources from untrusted external control spheres.

addresses: CWE-829

Enforcing installation policies prevents users from including functionality obtained from untrusted control spheres.

addresses: CWE-829

The inventory process requires identifying and recording the origin of all components, making inclusion of functionality from untrusted control spheres easier to detect during reviews.

addresses: CWE-829

Requiring approval and monitoring of maintenance tools prevents inclusion and execution of functionality obtained from untrusted sources.

addresses: CWE-829

Unowned portable devices represent untrusted control spheres; the prohibition prevents inclusion of functionality or data from such sources.

addresses: CWE-829

Strategy mandates assessment of third-party components and suppliers, directly reducing inclusion of functionality from untrusted control spheres.

addresses: CWE-829

Procedures can mandate supply-chain vetting and restrictions on functionality obtained from untrusted third-party or external control spheres.

addresses: CWE-829

Requires use of trusted sources and provenance tracking, tangibly limiting inclusion of functionality from untrusted control spheres.

References