VulnerabilityPublished 13 May 2026Updated 13 Aug 2026

CVE-2026-44578: vercel next.js · Server-Side Request Forgery (SSRF)

Affects vercel next.jsSource CVE Database V5

Not known to be exploited · public detection template (Nuclei) · 35% EPSS · CVSS 8.6 High : upgrade to 16.2.5 or 15.5.16 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

8.6High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 35.5% chance of exploitation in 30 days – higher than 98% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 16.2.5, 15.5.16, 16.2

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 May 2026
Detectable: evidence found.
nuclei template: Next.js WebSocket Upgrade Handler - SSRF
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade next.js to 16.2.5 or 15.5.16; next to 16.2 or 15.5.16.

Affected software

Product	Affected	Fixed in
vercelnext.js	Affected >=16.0.0 <16.2.5	Fixed in 16.2.5
vercelnext.js	Affected >=13.4.13 <15.5.16	Fixed in 15.5.16
npmnext`pkg:npm/next`Other threats	Affected >=13.4.13 <15.5.16 >=16.0.0 <16.2	Fixed in 15.5.16 16.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The vulnerability is fixed in Next.js versions 15.5.16 and 16.2.5. Users of affected versions should upgrade to these fixed versions to remediate the issue. Red Hat advisories indicate that no effective mitigation other than upgrading currently meets their criteria. Vercel-hosted deployments are not affected and require no action. Check the vendor advisory for the latest remediation guidance.

Description

Next.js is a React framework for building full-stack web applications. From 13.4.13 to before 15.5.16 and 16.2.5, self-hosted applications using the built-in Node.js server can be vulnerable to server-side request forgery through crafted WebSocket upgrade requests. An attacker can cause the server to proxy requests to arbitrary internal or external destinations, which may expose internal services or cloud metadata endpoints. Vercel-hosted deployments are not affected. This vulnerability is fixed in 15.5.16 and 16.2.5.

Impact

An attacker can exploit this SSRF vulnerability to make the vulnerable Next.js server proxy requests to arbitrary destinations, potentially exposing internal services or sensitive cloud metadata endpoints that are otherwise inaccessible. This can lead to confidentiality breaches of internal network resources. The vulnerability does not impact integrity or availability. The attack requires no privileges or user interaction and can be performed remotely over the network.

CWE-918Server-Side Request Forgery (opens in a new tab)
Base weaknessCWE Top 25 (2025): #22OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Implementation · Operation
If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
Implementation · Operation
If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.6.1 (opens in a new tab)
V5.2.6 (opens in a new tab)
Attack patterns
Server Side Request Forgery (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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CVE-2026-44578: vercel next.js · Server-Side Request Forgery (SSRF)

Exploitation evidence

What to do

Affected software

Description

Impact

Nuclei detection templates

Proofs of concept on GitHub

References

Community reviews

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Aug 2026, 13:04 UTC

Public exploits and detectiona Nuclei detection template, GitHub proofs of concept

WeaknessesCWE-918

Technical details

References

Community reviews

Related threats