How severe is CVE-2025-49826?

CVE-2025-49826 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-49826 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-49826?

CVE-2025-49826 primarily affects Vercel Next.js. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-49826?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-49826 have an EU (EUVD) identifier?

Yes. CVE-2025-49826 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-19910.

When was CVE-2025-49826 published?

CVE-2025-49826 was published on 2025-07-03 and last updated on 2026-06-17.

CVE-2025-49826

CVE-2025-49826 is a high-severity vulnerability in Vercel Next.js with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-444.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-19910
Weakness: CWE-444
Affected product: Vercel Next.js
Published: 2025-07-03
Last modified: 2026-06-17

Description

Next.js is a React framework for building full-stack web applications. From versions 15.0.4-canary.51 to before 15.1.8, a cache poisoning bug leading to a Denial of Service (DoS) condition was found in Next.js. This issue does not impact customers hosted on Vercel. Under certain conditions, this issue may allow a HTTP 204 response to be cached for static pages, leading to the 204 response being served to all users attempting to access the page. This issue has been addressed in version 15.1.8.

Frequently asked questions

What is CVE-2025-49826?: Next.js is a React framework for building full-stack web applications. From versions 15.0.4-canary.51 to before 15.1.8, a cache poisoning bug leading to a Denial of Service (DoS) condition was found in Next.js. This issue does not impact customers hosted on Vercel. Under certain conditions, this issue may allow a HTTP 204 response to be cached for static pages, leading to the 204 response being served to all users attempting to access the page. This issue has been addressed in version 15.1.8.
How severe is CVE-2025-49826?: CVE-2025-49826 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-49826 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-49826?: CVE-2025-49826 primarily affects Vercel Next.js. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-49826?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-49826 have an EU (EUVD) identifier?: Yes. CVE-2025-49826 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-19910.
When was CVE-2025-49826 published?: CVE-2025-49826 was published on 2025-07-03 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:*
cpe:2.3:a:vercel:next.js:15.0.4:canary51:*:*:*:node.js:*:*
cpe:2.3:a:vercel:next.js:15.0.4:canary52:*:*:*:node.js:*:*

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