What’s Vulnerable › Vulnerabilities

CVE-2026-9177: Server-Side Template Injection in SecureTransport's Apache Velocity mail templates

• Severity: critical (CVSS 9.4 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-29 · updated 2026-10-23
• Weakness: CWE-1336

Description

A Server-Side Template Injection (SSTI) vulnerability was identified in the mail template functionality of the Axway SecureTransport product in version 5.5-20260326. This flaw allows an attacker with admin privileges to inject arbitrary Java code expressions, which are executed server-side when the template is rendered (i.e., during email sending). Successful exploitation of this flaw allows an attacker to execute arbitrary code on the server that results in full host compromise. This issue affects all Axway SecureTransport versions prior 5.5-20260528 update.

Affected products

• Axway SecureTransport: from 5.5-20260326 before 5.5-20260528 — fixed in 5.5-20260528

How to fix

Upgrade to a fixed version: Axway SecureTransport 5.5-20260528. Check the vendor advisory for mitigations.

References

• https://docs.hackjiji.org/blog/cve-2026-9177-ssti-in-securetransport-mft-gateway
• https://support.axway.com/news/4882/lang/en
• https://www.toreon.com/CVE-2026-9177

Get alerted when CVE-2026-9177 or the next vulnerability affects your stack