VulnerabilityModified

CVE-2026-44575

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.

HIGH 7.5EPSS 1.59%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.59%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS: 1.59% probability · 76th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-288, CWE-551
Affected: vercel/next.js
Source: security-advisories@github.com

EPSS trend

EPSS 1.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.