Is CVE-2026-33659 actively exploited?

No active exploitation of CVE-2026-33659 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-33659 be exploited remotely?

Yes. CVE-2026-33659 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-33659?

CVE-2026-33659 has a CVSS score of 3.5 (LOW).

HOME VULNERABILITIESCVE-2026-33659

LOW

CVE-2026-33659

CWE-367Published: April 13, 2026· Updated: Apr 17, 2026

3.5

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:11.7th

Official 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.

NVD Source

Technical Analysis

CVE-2026-33659 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.