Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NSummary
CVE-2026-25890 is a high-severity Use of Incorrectly-Resolved Name or Reference (CWE-706) vulnerability in Filebrowser Filebrowser. Its CVSS base score is 8.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked at the 38th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-25890 affects File Browser, a web-based file management interface for uploading, deleting, previewing, renaming, and editing files within specified directories, in versions prior to 2.57.1. The vulnerability enables an authenticated user to bypass the application's "Disallow" file path rules by modifying the request URL, such as by adding multiple slashes (e.g., //private/) to the path. This causes the authorization check to fail matching the rule, while the underlying filesystem correctly resolves the path, resulting in unauthorized access to restricted files. It has a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N) and is associated with CWE-706 (Use of Incorrectly-Resolved Name Into a Namespace) and CWE-863 (Incorrect Authorization).
An attacker with low-privilege authenticated access (PR:L) can exploit this vulnerability remotely over the network (AV:N) with low attack complexity and no user interaction required. By crafting requests with multiple slashes in disallowed paths, they bypass restrictions to access, preview, rename, edit, or delete sensitive files outside the permitted scope, achieving high impacts on confidentiality and integrity but no availability disruption.
The issue is addressed in File Browser version 2.57.1. The GitHub security advisory (GHSA-4mh3-h929-w968) details the vulnerability, the release notes for v2.57.1 confirm the fix, and the patching commit (489af403a19057f6b4b1dc0e48cbb26a202ef9) implements the resolution to properly handle path normalization in authorization checks. Security practitioners should upgrade to 2.57.1 or later and review access controls for file paths.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-6866
Vulnerability Data
File Browser provides a file managing interface within a specified directory and it can be used to upload, delete, preview, rename and edit files. Prior to 2.57.1, an authenticated user can bypass the application's "Disallow" file path rules by modifying…
more
the request URL. By adding multiple slashes (e.g., //private/) to the path, the authorization check fails to match the rule, while the underlying filesystem resolves the path correctly, granting unauthorized access to restricted files. This vulnerability is fixed in 2.57.1.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
- 5 hardening rules · 3 OS baselines
—
Mitigating Controls (NIST 800-53 r5) AI
AC-3 directly requires correct enforcement of authorization decisions on every access request, structurally preventing incorrect checks.
AC-24 ensures access-control decisions are made and applied consistently, reducing the chance of an incorrect authorization result.
A reference monitor that is always invoked and tamper-proof forces every authorization decision through a verified, correct path.
Information flow enforcement can constrain flows that result from an incorrectly resolved name or reference.
Least-privilege assignments shrink the set of authorizations that must be checked correctly, limiting exposure to flawed checks.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Defining, enforcing, and reviewing access authorizations and least privilege directly prevents incorrect authorization checks.
Secure-development practices directly prevent incorrect name/reference resolution bugs during coding.
Logical segmentation and access controls reduce the chance an out-of-sphere resolution succeeds.
Hardened configuration baselines can constrain allowable name-to-resource mappings.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect incorrect name or reference resolution through fuzzing and negative test cases.
Requiring consistency between access rights and classification plus formal approval steps ensures that the authorization logic correctly distinguishes between entities that should and should not be granted access.
Enforcing policy-driven approval and role-change reviews stops incorrect or stale authorization decisions from remaining in effect after job changes or terminations.
Network segmentation and routing policies reduce the chance that a mis-resolved name leads to an unintended external resource.
Segregated networks limit the blast radius when a name or reference resolves outside the intended control sphere.
Secure SDLC practices include design reviews that can catch incorrect name or reference handling before deployment.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-863
- V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863
RHEL 7 (1 rule)
- V-204430 The Red Hat Enterprise Linux operating system must be configured so that users must re-authenticate for privilege escalation. prevents CWE-863
RHEL 8 (1 rule)
- V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863