GHSA-85jm-cwp2-mvpv

Suggest an improvement
Source
https://github.com/advisories/GHSA-85jm-cwp2-mvpv
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-85jm-cwp2-mvpv/GHSA-85jm-cwp2-mvpv.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-85jm-cwp2-mvpv
Aliases
  • CVE-2026-48796
Published
2026-06-30T18:36:12Z
Modified
2026-06-30T18:45:32.512557203Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N CVSS Calculator
Summary
CefSharp.Common: `FolderSchemeHandlerFactory` path boundary check can expose files outside the configured root folder
Details

Summary

FolderSchemeHandlerFactory was intended to restrict served files to a configured rootFolder, but its path validation used a raw string prefix check. A request could escape to a sibling directory whose full path starts with the root folder path, allowing files outside the configured root to be served.

Details

In affected versions, FolderSchemeHandlerFactory canonicalized rootFolder, decoded the request path, combined it with the root, and then allowed the file when:

filePath.StartsWith(rootFolder, StringComparison.OrdinalIgnoreCase)

This does not enforce a directory boundary. For example, /tmp/app/www2/secret.txt starts with /tmp/app/www, but www2 is a sibling of www, not a child. The same issue applies on Windows, for example C:\app\www2\secret.txt starts with C:\app\www.

The affected code was reviewed at commit b5fef3bb4bc58798c95170078c41de92cfe9066e, assembly version 147.0.100.

PoC

Set rootFolder to a directory named www and create a sibling directory named www2:

<temp>/www/index.html
<temp>/www2/secret.txt

Register FolderSchemeHandlerFactory for <temp>/www, then request:

https://folderschemehandlerfactory.test/..%2fwww2/secret.txt

The request path is URL-decoded to ../www2/secret.txt, combined with <temp>/www, and canonicalized to:

<temp>/www2/secret.txt

Because <temp>/www2/secret.txt starts with <temp>/www as a string prefix, the affected check passes and secret.txt is served from outside rootFolder.

Expected vulnerable result: HTTP 200 with the contents of <temp>/www2/secret.txt.

Expected fixed result: 404 or equivalent not-found response because the resolved file is outside rootFolder.

Impact

Applications using FolderSchemeHandlerFactory for a custom scheme or registered HTTP/HTTPS scheme may expose local files outside the intended served directory. This is most relevant when sensitive sibling directories share the root path prefix, such as www/www2, public/public_backup, or static/static-secrets.

An attacker must be able to cause the embedded browser to request URLs handled by the affected scheme registration.

Database specific 
{
    "nvd_published_at": null,
    "severity": "MODERATE",
    "cwe_ids": [
        "CWE-22"
    ],
    "github_reviewed_at": "2026-06-30T18:36:12Z",
    "github_reviewed": true
}
References

Affected packages

NuGet / CefSharp.Common

Package

Name
CefSharp.Common
View open source insights on deps.dev
Purl
pkg:nuget/CefSharp.Common

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
148.0.90

Affected versions

31.*
31.0.0-pre1
33.*
33.0.0
33.0.2
33.1.0-pre01
37.*
37.0.0-pre01
37.0.0-pre02
37.0.0
37.0.1
37.0.2
37.0.3
39.*
39.0.0-pre01
39.0.0-pre02
39.0.0-pre03
39.0.0
39.0.1
39.0.2
41.*
41.0.0-pre01
41.0.0
41.0.1
43.*
43.0.0-pre01
43.0.0-pre02
43.0.0
43.0.1
45.*
45.0.0-pre01
45.0.0
47.*
47.0.0-pre01
47.0.0
47.0.1
47.0.2
47.0.3
47.0.4
49.*
49.0.0-pre01
49.0.0-pre02
49.0.0
49.0.1
51.*
51.0.0-pre01
51.0.0-pre02
51.0.0
53.*
53.0.0-pre01
53.0.0
53.0.1
55.*
55.0.0-pre01
55.0.0
57.*
57.0.0-pre01
57.0.0
62.*
62.0.0-pre01
62.0.0-proprietary-codecs
62.0.0-proprietary-codecs2
63.*
63.0.0-pre01
63.0.0-pre02
63.0.0-pre03
63.0.0
63.0.1
63.0.2
63.0.3
65.*
65.0.0-pre01
65.0.0-pre02
65.0.0
65.0.1
67.*
67.0.0-pre01
67.0.0
69.*
69.0.0-pre01
69.0.0
71.*
71.0.0-pre01
71.0.0
71.0.1
71.0.2
73.*
73.1.120-pre01
73.1.130
75.*
75.1.140-pre01
75.1.141
75.1.142
75.1.143
79.*
79.1.310-pre
79.1.350
79.1.360
81.*
81.3.20-pre
81.3.100
83.*
83.3.120-pre
83.4.20
84.*
84.3.10-pre
84.4.10
85.*
85.3.120-pre
85.3.121-pre
85.3.121
85.3.130
86.*
86.0.240-pre
86.0.241
87.*
87.1.130-pre
87.1.131-pre
87.1.132
88.*
88.2.40-pre
88.2.90
89.*
89.0.140-pre
89.0.170
90.*
90.5.70-pre
90.6.50
90.6.70
91.*
91.1.60-pre
91.1.160
91.1.210
91.1.211
91.1.230
92.*
92.0.250-pre
92.0.251
92.0.260
93.*
93.1.110-pre
93.1.111
93.1.140
94.*
94.3.0-pre
94.4.20
94.4.50
94.4.110
95.*
95.7.140-pre
95.7.141
96.*
96.0.140-pre
96.0.141
96.0.142
96.0.170
96.0.180
97.*
97.1.10-pre
97.1.11
97.1.12
97.1.60
97.1.61
98.*
98.1.190
98.1.210
99.*
99.2.90
99.2.120
99.2.140
100.*
100.0.120-pre
100.0.140
100.0.230
101.*
101.0.150
101.0.180
102.*
102.0.90
102.0.100
103.*
103.0.80
103.0.90
103.0.120
104.*
104.4.180
104.4.240
105.*
105.3.330
105.3.390
106.*
106.0.260
106.0.290
107.*
107.1.40
107.1.50
107.1.90
107.1.120
108.*
108.4.130
109.*
109.1.110
110.*
110.0.250
110.0.280
110.0.300
111.*
111.2.20
111.2.70
112.*
112.2.70
112.3.0
113.*
113.1.40
113.3.50
114.*
114.2.100
114.2.120
115.*
115.3.110
115.3.130
116.*
116.0.130
116.0.150
116.0.190
116.0.230
117.*
117.2.20
117.2.40
118.*
118.6.80
119.*
119.1.20
119.4.30
120.*
120.1.80
120.1.110
120.2.50
120.2.70
121.*
121.3.70
121.3.130
122.*
122.1.120
123.*
123.0.60
124.*
124.3.20
124.3.50
124.3.80
125.*
125.0.210
126.*
126.2.70
126.2.180
127.*
127.3.50
128.*
128.4.90
129.*
129.0.110
130.*
130.1.90
131.*
131.2.70
131.3.10
131.3.50
132.*
132.3.11
133.*
133.4.21
134.*
134.3.60
134.3.90
135.*
135.0.170
135.0.220
136.*
136.1.40
137.*
137.0.100
138.*
138.0.170
138.0.340
139.*
139.0.280
140.*
140.1.140
141.*
141.0.110
143.*
143.0.90
144.*
144.0.120
144.0.250
144.0.260
144.0.270
145.*
145.0.260
146.*
146.0.70
146.0.100
147.*
147.0.100

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-85jm-cwp2-mvpv/GHSA-85jm-cwp2-mvpv.json"