How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.

361,925

Total vulnerabilities in the database

CVE-2026-55372 — nukeviet / nukeviet

Server-Side Request Forgery (SSRF)

Summary

An unauthenticated attacker can coerce the server into issuing HTTP requests to an attacker-chosen host by spoofing the X Forwarded-Host (and X-Forwarded-Proto) request headers. The forwarded host is used, without validation, to build the URL that server_info_update() fetches with cURL, resulting in a Server-Side Request Forgery (SSRF) that requires no authentication.

Affected component

File: includes/ini.php — function server_info_update() (cURL sink)
File: vendor/vinades/nukeviet/Core/Server.php — standardizeHost() and the forwarded-header handling in the constructor (source of the tainted host)
Trigger: POST request containing the field __serverInfoUpdate=1, handled early in includes/ini.php before any authentication.

Details

NukeViet\Core\Server derives original_host / original_protocol from the X-Forwarded-Host / X-Forwarded-Proto headers and exposes them via getOriginalHost() / getOriginalProtocol(). These values are attacker-controlled and were not validated against the site's configured domains (my_domains).

In server_info_update() the tainted host and scheme are concatenated directly into a cURL URL:

$proto = $nv_Server-&gt;getOriginalProtocol();   // from X-Forwarded-Proto
$host  = $nv_Server-&gt;getOriginalHost();        // from X-Forwarded-Host
$ch = curl_init($proto . &#039;://&#039; . $host . NV_BASE_SITEURL . &#039;index.php?response_headers_detect=1&#039;);
curl_exec($ch);

Two factors made this reliably reachable:

The __serverInfoUpdate handler runs very early in includes/ini.php, before authentication, so the sink is reachable pre-auth.
The host sanitiser standardizeHost() stripped a trailing port only with the regex (\:[0-9]+)$, which is bypassed by appending a slash (e.g. 127.0.0.1:8081/): the string no longer ends in :digits, so the port survives and an arbitrary host:port reaches the cURL call.

Proof of Concept

POST /index.php HTTP/1.1
Host: &lt;victim&gt;
X-Forwarded-Proto: http
X-Forwarded-Host: &lt;attacker-controlled-host&gt;:&lt;port&gt;/
Content-Type: application/x-www-form-urlencoded
Content-Length: 20

__serverInfoUpdate=1

The server then issues a request to the attacker-supplied host, confirmed via an out-of-band interaction (DNS + HTTP) on a collaborator endpoint.

Impact

The SSRF is blind, HEAD-only, and uses a fixed request path (…/index.php?response_headers_detect=1):

The fetched response is stored server-side in the config_ini cache and is not reflected to the attacker, so internal data cannot be exfiltrated directly.
Because the path is fixed and not attacker-controlled, cloud metadata endpoints (e.g. 169.254.169.254/latest/meta-data/...) cannot be reached, and gopher:// / dict:// request smuggling cannot inject arbitrary payloads.

What an attacker can do: unauthenticated internal host/port discovery (connection success/timing, with the port reachable through the regex bypass), and poisoning of the cached server_headers (the SSRF target's response headers are stored and applied to the site).

Severity

Rated High rather than Critical, because the blind + fixed-path + HEAD design of the sink prevents data exfiltration, cloud credential theft, and internal RCE.

CVSS v3.1 Base Score: 7.2 (High)
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Weakness

Primary: CWE-918: Server-Side Request Forgery (SSRF)
Contributing: CWE-20 (Improper Input Validation), CWE-644 (Improper Neutralization of HTTP Headers used by downstream components / trusting X-Forwarded-*).

Remediation

Fixed by validating and normalising the forwarded values at the source and gating the request before the sink:

standardizeHost() now extracts the host with parse_url() (defeats the :port/ bypass) and lower-cases it.
X-Forwarded-Proto is restricted to a {http, https} allow-list and falls back to the real server protocol otherwise.
X-Forwarded-Port is validated as numeric and within range.
The incoming host is checked against my_domains before includes/ini.php is reached; non-matching hosts are rejected/redirected, and server_info_update() additionally re-validates its target host against my_domains (defense in depth).

Workaround

Configure the reverse proxy / web server to strip or override client-supplied X-Forwarded-Host, X-Forwarded-Proto, and X-Forwarded-Port headers, and ensure my_domains is configured with the site's canonical domain(s).

Published: Jul 13, 2026
Updated: Jul 14, 2026
CVE: CVE-2026-55372
GHSA: GHSA-4chg-4752-w88r
Severity: High
Exploit:
CISA KEV:

CVSS v3:

Severity: High
Score: 7.2
AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CWEs:

CWE-918

Affected Software
References

Software	From	Fixed in
nukeviet / nukeviet	-	4.6.00

https://github.com/nukeviet/nukeviet/security/advisories/GHSA-4chg-4752-w88r

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.