How severe is CVE-2019-18935?

CVE-2019-18935 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2019-18935 being actively exploited?

Yes. CVE-2019-18935 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2019-18935?

CVE-2019-18935 affects Telerik Ui For Asp.net Ajax. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-18935?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2019-18935 have an EU (EUVD) identifier?

Yes. CVE-2019-18935 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2019-8608. It is also flagged as exploited in the EUVD (since 2021-11-03).

When was CVE-2019-18935 published?

CVE-2019-18935 was published on 2019-12-11 and last updated on 2026-06-17.

CVE-2019-18935

CVE-2019-18935 is a critical-severity vulnerability in Telerik Ui For Asp.net Ajax with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2021-11-03). The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 100% (100th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2021-11-03)
EU (EUVD) id: EUVD-2019-8608
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2021-11-03)
Weakness: CWE-502
Affected product: Telerik Ui For Asp.net Ajax
Published: 2019-12-11
Last modified: 2026-06-17

Description

Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a .NET deserialization vulnerability in the RadAsyncUpload function. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. Exploitation can result in remote code execution. (As of 2020.1.114, a default setting prevents the exploit. In 2019.3.1023, but not earlier versions, a non-default setting can prevent exploitation.)

Frequently asked questions

What is CVE-2019-18935?: Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a .NET deserialization vulnerability in the RadAsyncUpload function. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. Exploitation can result in remote code execution. (As of 2020.1.114, a default setting prevents the exploit. In 2019.3.1023, but not earlier versions, a non-default setting can prevent exploitation.)
How severe is CVE-2019-18935?: CVE-2019-18935 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-18935 being actively exploited?: Yes. CVE-2019-18935 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2019-18935?: CVE-2019-18935 affects Telerik Ui For Asp.net Ajax. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-18935?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2019-18935 have an EU (EUVD) identifier?: Yes. CVE-2019-18935 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2019-8608. It is also flagged as exploited in the EUVD (since 2021-11-03).
When was CVE-2019-18935 published?: CVE-2019-18935 was published on 2019-12-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:telerik:ui_for_asp.net_ajax:*:*:*:*:*:*:*:*

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