CVE-2026-44575

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:H/I:N/A:N

EPSS — probability of exploitation (30 days)

1.6%

74.6th percentile

CISA KEV

Not listed

Weakness / dates

CWE-551

Published 2026-05-13 · modified 2026-08-13

CVSS breakdown

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

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

Timeline

2026-05-13 — Published (NVD)
2026-08-13 — Last modified (NVD)

Description

Next.js is a React framework for building full-stack web applications. From 15.2.0 to before 15.5.16 and 16.2.5, App Router applications that rely on middleware or proxy-based checks for authorization can allow unauthorized access through transport-specific route variants used for segment prefetching. In affected configurations, specially crafted .rsc and segment-prefetch URLs can resolve to the same page without being matched by the intended middleware rule, which can allow protected content to be reached without the expected authorization check. This vulnerability is fixed in 15.5.16 and 16.2.5.

Affected

vercel

References

Official: NVD · CVE.org