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.
References
| Link | Resource |
|---|---|
| https://github.com/espocrm/espocrm/commit/dca03cc3458e487362c26c746378a2d4de9990b1 | Patch |
| https://github.com/espocrm/espocrm/releases/tag/9.3.4 | Release Notes |
| https://github.com/espocrm/espocrm/security/advisories/GHSA-6m4j-fwrx-crh7 | Exploit Vendor Advisory |
| https://github.com/espocrm/espocrm/security/advisories/GHSA-6m4j-fwrx-crh7 | Exploit Vendor Advisory |
Configurations
History
22 Apr 2026, 00:07
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/espocrm/espocrm/commit/dca03cc3458e487362c26c746378a2d4de9990b1 - Patch | |
| References | () https://github.com/espocrm/espocrm/releases/tag/9.3.4 - Release Notes | |
| References | () https://github.com/espocrm/espocrm/security/advisories/GHSA-6m4j-fwrx-crh7 - Exploit, Vendor Advisory | |
| First Time |
Espocrm espocrm
Espocrm |
|
| CPE | cpe:2.3:a:espocrm:espocrm:*:*:*:*:*:*:*:* |
14 Apr 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/espocrm/espocrm/security/advisories/GHSA-6m4j-fwrx-crh7 - |
13 Apr 2026, 21:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-04-13 21:16
Updated : 2026-04-22 00:07
NVD link : CVE-2026-33659
Mitre link : CVE-2026-33659
CVE.ORG link : CVE-2026-33659
JSON object : View
Products Affected
espocrm
- espocrm
