Review reviewCritical

CVE-2026-34906

Simple SA Wirtualna Uczelnia

Server-Side Template Injection (SSTI) in Wirtualna Uczelnia allows an unauthenticated attacker to perform Remote Code Execution (RCE). In the endpoint redirectToUrl and parameter redirectUrlParameter, insufficient input validation permits injection of arbitrary template expressions that are executed on the server. Successful exploitation can allow an attacker to run remote commands, including establishing a reverse shell. This issue affects Wirtualna Uczelnia versions up to wu#2016.437.295#0#20260327_105545

CVSS
9.3
EPSS
0.56%
43.3% percentile
CISA KEV
Not listed
Published
2026.06.02
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.56%
Technical severityCVSS 9.3

Vulnerability overview

Server-Side Template Injection (SSTI) in Wirtualna Uczelnia allows an unauthenticated attacker to perform Remote Code Execution (RCE). In the endpoint redirectToUrl and parameter redirectUrlParameter, insufficient input validation permits injection of arbitrary template expressions that are executed on the server. Successful exploitation can allow an attacker to run remote commands, including establishing a reverse shell. This issue affects Wirtualna Uczelnia versions up to wu#2016.437.295#0#20260327_105545

Affected product and versions

Product
Simple SA Wirtualna Uczelnia
Affected versions
<= wu#2016.437.295#0#20260327_105545
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Simple SA Wirtualna Uczelnia and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE
CWE-1336