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TI-2026-35988 Aliases CVE-2026-48707

InstantCMS vulnerable to SSRF via upload redirect bypass allows internal network service scanning

Priority MEDIUM 48CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-918 and the CVSS impact.

Summary

InstantCMS is a free and open source content management system. Versions prior to 2.18.2 have a Server-Side Request Forgery (SSRF) vulnerability in the file upload functionality (`system/core/uploader.php` at lines 509-532). When the "upload from URL" feature follows an HTTP redirect, the redirected target URL bypasses the private IP address blacklist check. This allows authenticated users to scan and access internal network services. Version 2.18.2 contains a fix.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00267 18th percentileScored 2026-11-07
Fix Fixed icms2 (instantsoft): 2.18.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
instantsofticms2before 2.18.22.18.2Patch availableCNA
  • icms2 Vendorinstantsoft Affected before 2.18.2 Fixed in 2.18.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:instantcms:instantcms:*:*:*:*:*:*:*:*——InstantCMS
  • cpe:2.3:a:instantcms:instantcms:*:*:*:*:*:*:*:* Versions — — ·InstantCMS

Remediation

  • Fix · CNA icms2 (instantsoft) Fixed in 2.18.2

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-48707

References

Other 2

  • TI-2023-03877 SQL Injection in instantsoft/icms2 CVSS 3.1CRITICAL 9.1
  • TI-2024-20589 SQL injection in index_chart_data action CVSS 3.1HIGH 7.2
  • TI-2023-04538 SQL Injection in instantsoft/icms2 CVSS 3.1HIGH 7.2
  • TI-2025-36697 InstantCMS vulnerable to Server-Side Request Forgery via package installer CVSS 3.1HIGH 7.2
  • TI-2023-04291 Cross-site Scripting (XSS) - Reflected in instantsoft/icms2 CVSS 3.1MEDIUM 6.1
  • TI-2026-39443 InstantCMS has Remote Code Execution in package installer CVSS 3.1MEDIUM 5.5
See all 25 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences