Interpretation Conflict in fast-uri - CVE-2026-18446

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Main Vulnerability Database Vulnerabilities #VU140701

Interpretation Conflict in fast-uri - CVE-2026-18446

Published: August 1, 2026


Vulnerability identifier: #VU140701
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-18446
CWE-ID: CWE-436
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to bypass host-based policy checks and steer requests to an unintended destination.

The vulnerability exists due to interpretation conflict in the fast-uri URI parser when parsing references that use backslash-based authority introducers. A remote attacker can supply a specially crafted URL to bypass host-based policy checks and steer requests to an unintended destination.

The issue arises from inconsistent host extraction between fast-uri and Node's WHATWG URL handling for special schemes.


Affected software

fast-uri
ApplinX
Bitbucket Data Center
Bamboo Data Center
Jira Software Data Center
Jira Service Management Data Center
Informix Dynamic Server

How to mitigate CVE-2026-18446

Install security update from vendor's website.

fast-uri - addressed in versions 2.4.4, 3.1.5, 4.1.2
Bitbucket Data Center - update to 9.4.23
Bamboo Data Center - update to 10.2.22
Jira Software Data Center - addressed in versions 10.3.25, 11.3.1
Jira Service Management Data Center - addressed in versions 10.3.25, 11.3.1
Informix Dynamic Server - addressed in versions 14.10.FC14W1, 15.0.1.16

External References

Related Security Bulletins