How severe is CVE-2026-34906?

CVE-2026-34906 has a CVSS 4.0 base score of 9.3, rated critical severity.

Is CVE-2026-34906 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-34906?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-34906 have an EU (EUVD) identifier?

Yes. CVE-2026-34906 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33902.

When was CVE-2026-34906 published?

CVE-2026-34906 was published on 2026-06-02 and last updated on 2026-06-17.

CVE-2026-34906

CVE-2026-34906 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1336.

Key facts

Severity: Critical (CVSS 4.0 base score 9.3)
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-33902
Weakness: CWE-1336
Published: 2026-06-02
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2026-34906?: 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
How severe is CVE-2026-34906?: CVE-2026-34906 has a CVSS 4.0 base score of 9.3, rated critical severity.
Is CVE-2026-34906 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-34906?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-34906 have an EU (EUVD) identifier?: Yes. CVE-2026-34906 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33902.
When was CVE-2026-34906 published?: CVE-2026-34906 was published on 2026-06-02 and last updated on 2026-06-17.

References

Other CWE-1336 vulnerabilities

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CVE-2026-9558 — Critical (CVSS 9.9): A Server-Side Template Injection (SSTI) vulnerability exists in Mautic's theme engine. The platform renders uploaded…
CVE-2026-33897 — Critical (CVSS 9.9): Incus is a system container and virtual machine manager. Prior to version 6.23.0, instance template files can be used…
CVE-2026-1868 — Critical (CVSS 9.9): GitLab has remediated a vulnerability in the Duo Workflow Service component of GitLab AI Gateway affecting all versions…

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