SB2026072195 - Interpretation Conflict in fast-uri
Published: July 21, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Interpretation Conflict (CVE-ID: CVE-2026-13676)
CWE-ID: CWE-436 - Interpretation Conflict
CVSSv4: 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]
The vulnerability allows a remote attacker to modify data on the system.
The vulnerability exists due to fast-uri fail to canonicalize Unicode (IDN) hostnames for HTTP-family URLs. The IDN conversion path calls a helper that does not exist on the global URL constructor, silently leaving the host in its original Unicode form while normalize() and equal() still return values that differ from a WHATWG-compatible URL parser. A remote attacker can trigger the vulnerability to modify data on the system.
Remediation
Install update from vendor's website.
References
- https://cna.openjsf.org/security-advisories.html
- https://github.com/fastify/fast-uri/security/advisories/GHSA-4c8g-83qw-93j6
- https://access.redhat.com/errata/RHSA-2026:37186
- https://access.redhat.com/errata/RHSA-2026:37585
- https://access.redhat.com/errata/RHSA-2026:37628
- https://access.redhat.com/errata/RHSA-2026:40118
- https://access.redhat.com/errata/RHSA-2026:40262
- https://access.redhat.com/errata/RHSA-2026:40945
- https://access.redhat.com/errata/RHSA-2026:41066
- https://access.redhat.com/security/cve/CVE-2026-13676
- https://bugzilla.redhat.com/show_bug.cgi?id=2494197
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-13676.json