In Eclipse Theia versions 0.7.0 and up until including 1.73.1, the PreferenceUtils.merge function in @theia/core recursively merges preference values without rejecting prototype-related keys (__proto__, constructor, prototype). Because this function is invoked by PreferenceServiceImpl.doResolve for every preference resolution across scopes (default, user, workspace, folder), a crafted preference value in a workspace settings file (.theia/settings.json or .vscode/settings.json) can pollute Object.prototype when the user opens the workspace, potentially altering application logic across the Theia process.
{
"cna_assigner": "eclipse",
"cwe_ids": [
"CWE-1321"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/14xxx/CVE-2026-14574.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0.7.0"
},
{
"fixed": "1.74.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"cpe": "cpe:2.3:a:eclipse:theia:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0.7.0"
},
{
"fixed": "1.74.0"
}
],
"source": "CPE_RANGE"
}
]
}