CVE-2026-13676

Medium

Elevated severity or exploit probability.

CVSS base

7.5 HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS — probability of exploitation (30 days)

0.5%

40.5th percentile

CISA KEV

Not listed

Weakness / dates

CWE-551

Published 2026-06-29 · modified 2026-09-11

CVSS breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector	N	Network
Attack Complexity	L	Low
Privileges Required	N	None
User Interaction	N	None
Scope	U	Unchanged
Confidentiality	N	None
Integrity	H	High
Availability	N	None

Timeline

2026-06-29 — Published (NVD)
2026-09-11 — Last modified (NVD)

Description

fast-uri versions 2.3.1 through 3.1.2 and 4.0.0 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. Applications that use fast-uri to enforce host-based policy (denylists, loopback filtering, redirect validation, outbound proxy routing) before passing the same URL to Node's URL or fetch can be bypassed when the two implementations resolve the same input to different hosts. Patches: upgrade to fast-uri 3.1.3 for the 3.x line or 4.0.1 for the 4.x line. Workarounds: enforce host policy using the same URL parser used for the actual request, or reject non-ASCII hosts before policy checks.

Affected

openjsf

References

Official: NVD · CVE.org