AUGUST 4, 2026
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Case File

CVE-2026-33659

LOW · CVSS 3.5 EPSS 0.33% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2026-04-13 · Last synced 2026-08-04

CyberRota Analysis

This is a low severity vulnerability with a CVSS score of 3.5. Public exploit code or proof-of-concept references have been detected in its references. It may be remotely exploitable. Exploitation may require the attacker to be authenticated.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit poc remote code execution code execution

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-33659
Severity
LOW
CVSS
3.5
EPSS
0.33%

Original NVD Description

EspoCRM is an open source customer relationship management application. In versions 9.3.3 and below, the POST /api/v1/Attachment/fromImageUrl endpoint is vulnerable to Server-Side Request Forgery (SSRF) via a DNS rebinding (TOCTOU) condition. Host validation uses dns_get_record() but the actual HTTP request resolves hostnames through curl's internal resolver (gethostbyname()), allowing the two lookups to return different IP addresses for the same hostname. A secondary issue exists where an empty DNS result (due to DNS failure, IPv6-only domains, or non-existent hostnames) causes the validation to implicitly allow the host without further checks. An authenticated attacker with default attachment creation access can exploit this gap to bypass internal IP restrictions and scan internal network ports, confirm the existence of internal hosts, and interact with internal HTTP-based services, though data extraction from binary protocol services and remote code execution are not possible through this endpoint. This issue has been fixed in version 9.3.4.

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