CVE-2026-33659: low-severity vulnerability in espocrm
EspoCRM: SSRF via DNS Rebinding in Attachment fromImageUrl Endpoint Allows Internal Network Access
Published · Updated
8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 3.5epss 0.4%
exploitation probability
0.4%top 68% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N
Affected products
espocrm · espocrmRelated CVEs — espocrm
In the same product, most dangerous first.
CVE-2026-33534MEDIUMEspoCRM has authenticated SSRF via internal-host validation bypass using alternative IPv4 notationEPSS 1.7%CVE-2025-52575MEDIUMEspoCRM vulnerable to LDAP Injection through Improper Neutralization of Special ElementsEPSS 0.7%CVE-2024-24818MEDIUMEspoCRM weakness in "Forgot password"EPSS 0.6%CVE-2026-33733HIGHEspoCRM has Admin TemplateManager path traversal that allows arbitrary file read write and deleteEPSS 0.6%CVE-2026-33656CRITICALEspoCRM vulnerable to authenticated RCE via Formula with path traversal in attachment `sourceId`, exploitable by admin userEPSS 0.6%CVE-2025-32789LOWEspoCRM Allows Potential Disclosure of Sensitive Information in the User Sorting FunctionEPSS 0.4%