CVE-2026-44573
HIGHDescription
Next.js is a React framework for building full-stack web applications. From 12.2.0 to before 15.5.16 and 16.2.5, Applications using the Pages Router with i18n configured and middleware/proxy-based authorization can allow unauthorized access to protected page data through locale-less /_next/data/<buildId>/<page>.json requests. In affected configurations, middleware does not run for the unprefixed data route, allowing an attacker to retrieve SSR JSON for protected pages without passing the intended authorization checks. This vulnerability is fixed in 15.5.16 and 16.2.5.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Exploit Intelligence
Moderate risk: more likely to be exploited than 54% of all known CVEs.
References
Related Vulnerabilities
Other CWE-863 (Incorrect Authorization) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2023-22518 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2023-38035 | Critical | 9.8 | 100% | KEV + Ransom | - |
| CVE-2022-46169 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2024-38856 | Critical | 9.8 | 99% | KEV | Fix |
| CVE-2025-29927 | Critical | 9.1 | 99% | - | Fix |
| CVE-2020-36289 | Medium | 5.3 | 99% | - | Fix |
Common questions
How do I fix CVE-2026-44573?
Upgrade next.js to 15.5.16 or later.
Is CVE-2026-44573 being actively exploited?
Not that we know of. CVE-2026-44573 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.76% is the estimated probability that it will be exploited in the next 30 days. That is higher than 54% of all scored CVEs.
How severe is CVE-2026-44573?
CVE-2026-44573 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-44573 affect?
Published advisories record a fix for next.js (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-13.