CVE-2026-61520: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-9wvj-rhhh-8292
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CVSS 7.7
CWE-918
Published
Advisory Summary

CVE-2026-61520 is a MODERATE (CVSS 7.7) security vulnerability vulnerability (CWE-918: Server-Side Request Forgery (SSRF)) affecting Software libraries in the Maven ecosystem. The weakness occurs when 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.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-61520 at a Glance

CVE Identifier CVE-2026-61520
GHSA Identifier GHSA-9wvj-rhhh-8292
Severity MODERATE
CVSS v3.1 Base Score 7.7
CWE Classification CWE-918: Server-Side Request Forgery (SSRF)
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-61520

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-61520, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-918: Server-Side Request Forgery (SSRF), where 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. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Simple Machines Forum 2.1 prior to commit 4bf35cf and 3.0 prior to commit b4d23df contains a server-side request forgery vulnerability in the image proxy that allows authenticated attackers to trigger internal HTTP requests by embedding attacker-controlled URLs in BBCode image tags, which the proxy fetches without validating resolved destination IPs against private address ranges, loopback, or link-local addresses. Attackers can leverage SMF's automatic HMAC signature generation for any embedded image URL to obtain valid signed proxy requests targeting internal services such as cloud instance metadata endpoints, internal web applications, and container network services.

References

NVD — CVE-2026-61520 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-61520
Security Fix Commit FIX COMMIT
https://github.com/SimpleMachines/SMF/commit/4bf35cf9e45573a5f55a6f52995086c1da89c096
Security Fix Commit FIX COMMIT
https://github.com/SimpleMachines/SMF/commit/b4d23dfd74a511587c605f9d294cefc3a75b4b26
www.vulncheck.com/advisories/simple-m... WEB
https://www.vulncheck.com/advisories/simple-machines-forum-ssrf-via-image-proxy

Frequently Asked Questions

What is CVE-2026-61520?
CVE-2026-61520 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-918: Server-Side Request Forgery (SSRF).
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-61520?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-61520?
CVE-2026-61520 has a CVSS v3.1 base score of 7.7 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.
What CWE is associated with CVE-2026-61520?
CVE-2026-61520 is classified under CWE-918: Server-Side Request Forgery (SSRF) (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.).
How can I check Maven dependencies for CVE-2026-61520?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9wvj-rhhh-8292",
  "modified" : "2026-07-14T21:32:25Z",
  "published" : "2026-07-14T21:32:25Z",
  "aliases" : [ "CVE-2026-61520" ],
  "details" : "Simple Machines Forum 2.1 prior to commit 4bf35cf and 3.0 prior to commit b4d23df contains a server-side request forgery vulnerability in the image proxy that allows authenticated attackers to trigger internal HTTP requests by embedding attacker-controlled URLs in BBCode image tags, which the proxy fetches without validating resolved destination IPs against private address ranges, loopback, or link-local addresses. Attackers can leverage SMF's automatic HMAC signature generation for any embedded image URL to obtain valid signed proxy requests targeting internal services such as cloud instance metadata endpoints, internal web applications, and container network services.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-61520"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/SimpleMachines/SMF/commit/4bf35cf9e45573a5f55a6f52995086c1da89c096"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/SimpleMachines/SMF/commit/b4d23dfd74a511587c605f9d294cefc3a75b4b26"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/simple-machines-forum-ssrf-via-image-proxy"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-918" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-14T21:17:06Z"
  }
}