VulnerabilityAwaiting Analysis

CVE-2026-9177

A Server-Side Template Injection (SSTI) vulnerability was identified in the mail template functionality of the Axway SecureTransport product in version 5.5-20260326.

CRITICAL 9.4EPSS 0.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 9.4 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.29% probability · 21th percentile
CISA KEV: Not listed
Weakness: CWE-1336
Source: 1c6b5737-9389-4011-8117-89fa251edfb2

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.