Cyber Resilience

CVE-2026-28786

Path Traversal in Openwebui Open Webui ≤ 0.8.6

Public PoCPath TraversalInfo Disclosure
Published
27 March 2026
Modified
30 March 2026
Patch / advisory
View advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0043 35th percentile
Risk Priority 37 floored blend · peak EPSS

Summary

CVE-2026-28786 is a medium-severity Path Traversal (CWE-22) vulnerability in Openwebui Open Webui. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 35th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

This vulnerability is AI-related — categorised as LLM Application Platforms; in the Privacy and Disclosure risk domain.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access ControlA10:2025 Mishandling of Exceptional Conditions

EU & UK References

Vulnerability Data

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.8.6, an unsanitized filename field in the speech-to-text transcription endpoint allows any authenticated non-admin user to trigger a `FileNotFoundError` whose message — including the…

more

server's absolute `DATA_DIR` path — is returned verbatim in the HTTP 400 response body, confirming information disclosure on all default deployments. Version 0.8.6 patches the issue.

CWE(s)
CWE-22CWE-209

AI Security AnalysisAI

AI Category
LLM Application Platforms
Risk Domain
Privacy and Disclosure
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: artificial intelligence, open webui

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1592.002 Software Reconnaissance
Adversaries may gather information about the victim's host software that can be used during targeting.
attack.mitre.org →
T1082 System Information Discovery Discovery
An adversary may attempt to get detailed information about the operating system and hardware, including version, patches, hotfixes, service packs, and architecture.
attack.mitre.org →
T1592 Gather Victim Host Information Reconnaissance
Adversaries may gather information about the victim's hosts that can be used during targeting.
attack.mitre.org →
T1595 Active Scanning Reconnaissance
Adversaries may execute active reconnaissance scans to gather information that can be used during targeting.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-44565Same product: Openwebui Open Webui
CVE-2024-7037Same product: Openwebui Open Webui
CVE-2026-44566Same product: Openwebui Open Webui
CVE-2024-6707Same product: Openwebui Open Webui
CVE-2024-13535Shared CWE-209, CWE-22
CVE-2024-13538Shared CWE-209, CWE-22
CVE-2024-3403Shared CWE-22
CVE-2026-29871Shared CWE-22
CVE-2026-4502Shared CWE-22
CVE-2026-23483Shared CWE-22

Affected Assets

openwebui
open webui
≤ 0.8.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V16.5.1
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

SI-11 Error Handling good match

si-11 directly requires error messages to avoid revealing exploitable information about the system or its data.

AC-3 Access Enforcement good match

Enforces the intended directory access authorizations that path traversal would otherwise bypass.

SI-10 Information Input Validation good match

Input validation directly neutralizes special path elements before pathname construction occurs.

AC-6 Least Privilege partial match

Least privilege reduces the impact of any unauthorized file access obtained via traversal.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require sanitized error handling to prevent sensitive data disclosure.

PR.PS-02 partial match
prevents

Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.

PR.AA-05 none match
prevents

PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.

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.

A.8.28 Secure coding mostly match
prevents

Secure coding standards explicitly forbid exposing sensitive data in errors.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches path traversal via static/dynamic analysis.

A.8.15 Logging partial match
degrades

Logging policy can require suppression of sensitive data in error messages.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.

A.8.26 Application security requirements partial match
prevents

Application security requirements include rules for safe file handling and canonicalization.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles require least-privilege file access and directory isolation.

References