CVE-2025-21391
Microsoft Windows Storage Link Following Vulnerability
CVSS
7.1
High
EPSS
2.3%
p83
KEV
YES
Feb 11, 2025
Exploit Today
75
0-100
Published: Feb 11, 2025 · Last modified: Sep 24, 2026 · CWE-59
2.3%EPSS · 30 days2.3%
2026-09-172026-10-15
Product
Microsoft / Windows
Vulnerability
Microsoft Windows Storage Link Following Vulnerability
Added to KEV
Feb 11, 2025
Remediate by
Mar 4, 2025
Known ransomware use
No
Summary description
Microsoft Windows Storage contains a link following vulnerability that could allow for privilege escalation. This vulnerability could allow an attacker to delete data including data that results in the service being unavailable.
Required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Notes
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21391 ; https://nvd.nist.gov/vuln/detail/CVE-2025-21391
Windows Storage Elevation of Privilege Vulnerability
CVECVSSEPSSKEVRExploitTitleMod.
CVE-2026-554805.7 MED—
——0OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, copy_model() in scheduler/ipp.c creates a predictable TempDir/<connection-number>.ppd path in an lp-group-writable directory and opens it as root without O_EXCL or O_NOFOLLOW. Exploitation requires an lp-group process able to write that directory to predict the connection-derived name and plant a symlink before the root open, while a privileged add-printer or modify-printer operation using a model PPD triggers copy_model(). The reporter treats an existing lp foothold and the privileged operation as distinct prerequisites, while the maintainer assesses high privileges because installing the relevant filter or administering the printer requires root or print-administrator access. If the race succeeds, the root scheduler follows the symlink and truncates or overwrites a root-writable target with generated PPD data, compromising file integrity or availability. This issue is fixed in version 2.4.20.8hCVE-2026-53882—38.9%
——12An improper link resolution before file access ('link following') vulnerability has been reported to affect Virtualization Station. If a remote attacker gains a user account, they can then exploit the vulnerability to compromise the security of the system.
We have already fixed the vulnerability in the following version:
Virtualization Station 4.1.1.130 and later10hCVE-2026-1108606.1 MED2.3%
——1GitPython from 3.1.62 before 3.2.0 contains a symlink-following flaw in Submodule.move(), which checks the destination only lexically and does not reject symbolic links in intermediate path components. An untrusted repository can commit a symlink such as vendor pointing outside the worktree, so an application moving an initialized submodule beneath it relocates the checkout externally and corrupts the index and .gitmodules.6hCVE-2026-1041096.8 MED23.6%
——7FileRise is a self-hosted web-based file manager with multi-file upload, editing, and batch operations. Prior to 3.23.0, FileRise validates archive entry names but extracts them directly into the authorized live destination before validating resolved paths. If that destination already contains a symlink to a directory outside the storage root, an authenticated non-administrator with extract permission who can upload or otherwise place an attacker-controlled ZIP in that folder can place an ordinary archive entry beneath the link. ZipArchive::extractTo() can then overwrite an external file, and post-extraction cleanup can delete that target through the same linked parent, only where the FileRise process has the required filesystem write or removal permission. The advisory does not establish that the attacker can create the prerequisite symlink through FileRise. This issue is fixed in version 3.23.0.1dCVE-2026-554984.8 MED18.9%
——6FileRise is a self-hosted web-based file manager with multi-file upload, editing, and batch operations. Prior to 3.15.0, FileRise public shared-folder links with subfolder browsing enabled can follow a symbolic link inside the shared folder to a sibling directory under the upload root. An unauthenticated holder of a valid share token can use shared-folder listing, direct download, or ZIP creation to access files outside the folder that was actually shared. The flaw occurs because the affected shared-folder paths resolve symlinks without enforcing the original shared folder as the real-path boundary. This issue is fixed in version 3.15.0.10hCVE-2026-1107677.5 HIG33.4%
——10Gitingest through 0.3.1 contains a symlink following vulnerability in ingest_query single-file blob ingestion that allows unauthenticated attackers to read server files by submitting symlink blob URLs. Attackers can commit a symlink to a public repository and submit its blob URL, causing the server to return any file the service user can read, up to 10 MB.7h