Skip to main content
Mallory
Critical

Unauthenticated SSTI RCE in Wirtualna Uczelnia redirectToUrl

IdentifiersCVE-2026-34906CWE-1336· Improper Neutralization of Special…

CVE-2026-34906 is a server-side template injection (SSTI) vulnerability in Simple SA's Wirtualna Uczelnia. The flaw is present in the redirectToUrl endpoint, specifically in handling of the redirectUrlParameter parameter. Insufficient input validation allows an attacker to inject arbitrary template expressions that are evaluated on the server. Because the injected expressions execute within the server-side template engine context, an unauthenticated remote attacker can achieve remote code execution. The issue affects Wirtualna Uczelnia versions up to and including wu#2016.437.295#0#20260327_105545.

Share:
For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation results in unauthenticated remote code execution on the affected server. An attacker can execute arbitrary commands, potentially establish a reverse shell, fully compromise the application context, access or modify server-side data handled by the application, and use the foothold for further post-exploitation activity.

Mitigation

If you can’t patch tonight, do this now.

No vendor workaround is specifically documented in the provided content. As interim mitigation, restrict external access to the application where feasible, closely monitor and filter requests targeting redirectToUrl and redirectUrlParameter, and deploy compensating controls such as WAF signatures or request filtering to block template-expression payloads until the product is upgraded.

Remediation

Patch, then assume compromise.

Upgrade Wirtualna Uczelnia to a version newer than wu#2016.437.295#0#20260327_105545. The underlying fix should ensure that untrusted input supplied via redirectUrlParameter is never evaluated as a template expression and that strict server-side input validation and safe template handling are enforced in the redirectToUrl endpoint.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity5

Community discussion across Reddit, Mastodon, and other social sources.