9.8
CRITICAL CVSS 3.1
CVE-2026-75627
Bastillion Authentication Bypass via Path-Prefix Routing Mismatch
Description

Bastillion fails to properly validate request URI paths in its controller dispatcher, allowing unauthenticated attackers to bypass authentication filters by prefixing requests with arbitrary path segments. Attackers can access administrative controllers to read user listings, create manager accounts, and register managed systems, gaining control over SSH access to the managed fleet.

INFO

Published Date :

Aug. 18, 2026, 11:16 a.m.

Last Modified :

Aug. 18, 2026, 6:19 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-75627 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 CRITICAL [email protected]
CVSS 3.1 CRITICAL MITRE-CVE
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Properly validate request URI paths to prevent unauthenticated access to administrative functions.
  • Validate all request URI paths.
  • Ensure authentication filters are applied universally.
  • Apply security patches for Bastillion.
  • Review access control configurations.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-75627 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-75627 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-75627 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-75627 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 18, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/bastillion-io/Bastillion/issues/669
    Added SSVC {'id': 'CVE-2026-75627', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-18T18:06:21.598629Z'}
  • New CVE Received by [email protected]

    Aug. 18, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/bastillion-io/Bastillion', 'vendor': 'bastillion-io', 'product': 'Bastillion', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '5.1.0'}], 'packageURL': 'pkg:npm/bastillion', 'defaultStatus': 'unaffected'}]
    Added Description Bastillion fails to properly validate request URI paths in its controller dispatcher, allowing unauthenticated attackers to bypass authentication filters by prefixing requests with arbitrary path segments. Attackers can access administrative controllers to read user listings, create manager accounts, and register managed systems, gaining control over SSH access to the managed fleet.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-288
    Added Reference https://github.com/bastillion-io/Bastillion
    Added Reference https://github.com/bastillion-io/Bastillion/blob/master/src/main/java/loophole/mvc/base/BaseKontroller.java
    Added Reference https://github.com/bastillion-io/Bastillion/commit/d759fb686a1a097b1b026e286fd9b20e5ba349c8
    Added Reference https://github.com/bastillion-io/Bastillion/issues/669
    Added Reference https://www.vulncheck.com/advisories/bastillion-authentication-bypass-via-path-prefix-routing-mismatch
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.