CVE-2025-66221

Werkzeug is a comprehensive WSGI web application library. Prior to version 3.1.4, Werkzeug's safejoin function allows path segments with Windows device names. On Windows, there are special device names such as CON, AUX, etc that are implicitly present and readable in every directory. sendfromdirectory uses safejoin to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely. This issue has been patched in version 3.1.4.

Database specific

{
    "cna_assigner": "GitHub_M",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66221.json",
    "cwe_ids": [
        "CWE-67"
    ]
}

References

Affected packages

Git / github.com/pallets/werkzeug

Affected ranges

Type: GIT
Repo: https://github.com/pallets/werkzeug
Events: Introduced

0 Unknown introduced commit / All previous commits are affected

Fixed

1c7beb671d1af67a07684ffa1fffdb0fc76c7fa4

Affected versions

0.*

0.1

0.10

0.10.1

0.10.2

0.10.3

0.10.4

0.11

0.11.1

0.11.10

0.11.11

0.11.12

0.11.13

0.11.14

0.11.15

0.11.2

0.11.3

0.11.4

0.11.5

0.11.6

0.11.7

0.11.8

0.11.9

0.12

0.12.1

0.12.2

0.13

0.14

0.14.1

0.14.x

0.15.0

0.15.1

0.15.2

0.15.3

0.15.4

0.15.5

0.15.6

0.15.x

0.16.0

0.16.1

0.16.x

0.2

0.3

0.3.1

0.4

0.4.1

0.5

0.5.1

0.6

0.6.1

0.6.2

0.7

0.8

0.8.1

0.8.2

0.8.3

0.9

0.9.1

0.9.2

0.9.3

0.9.4

0.9.5

0.9.6

1.*

1.0.0

1.0.0rc1

1.0.1

1.0.x

2.*

2.0.0

2.0.0rc1

2.0.0rc2

2.0.0rc3

2.0.0rc4

2.0.0rc5

2.0.1

2.0.2

2.0.3

2.0.x

2.1.0

2.1.1

2.1.2

2.1.x

2.2.0

2.2.0a1

2.2.1

2.2.2

2.2.3

2.2.x

2.3.0

2.3.1

2.3.2

2.3.3

2.3.4

2.3.5

2.3.6

2.3.7

2.3.8

2.3.x

3.*

3.0.2

3.0.3

3.0.4

3.0.5

3.0.6

3.0.x

3.1.0

3.1.1

3.1.2

3.1.3