Vulnerability in Eclipse Theia
CVE-2026-46580
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, 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.
EPSS: 0.005 (42.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Eclipse Theia
- Eclipse Foundation Theia — versions 0
Weakness classification (CWE)
References
- emo@eclipse.org (Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-46580?
- CVE-2026-46580 is a high-severity vulnerability in Eclipse Theia, classified under Inclusion of Functionality from Untrusted Control Sphere. CVSS score: 8.8/10. Published 2026-06-18.
- How severe is CVE-2026-46580?
- High severity. CVSS v3 base score is 8.8 out of 10.