Exploited CVEs / Apache / CVE-2020-17519

CVE-2020-17519

Apache Flink Improper Access Control Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2024-06-13 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.

Risk summary

HighCISA KEV

7.5

CVSS v3 base

98%

EPSS exploit probability

High

Severity

2024-05-23

Added to KEV

2024-06-13 (past due)

CISA due date

Actively exploited Apache Flink vulnerability, High severity, CVSS v3 7.5. Added to the CISA KEV catalog 2024-05-23.

Senserva AI read on CVE-2020-17519 CISA required action Official fix for CVE-2020-17519 Admin questions

Senserva AI Opinion for CVE-2020-17519

Apache Flink's JobManager REST interface can be tricked into serving any file the process can read on the local filesystem, no authentication involved. With a 98 percent EPSS probability and a May 2024 KEV listing, exploitation is effectively guaranteed for exposed instances. Data-platform components like Flink often keep credentials in configuration files, exactly what this flaw hands over.

Do this: Ensure Flink JobManager REST interfaces are unreachable from untrusted networks and upgrade past the CVE-2020-17519 fix.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2020-17519

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2020-17519, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2020-17519.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2020-17519: Apache Flink Improper Access Control Vulnerability
- Affected: Apache Flink
- Severity: High, CVSS v3 7.5; EPSS 30-day exploitation probability 98%
- Added to CISA KEV: 2024-05-23; federal remediation due 2024-06-13
- Ransomware-linked: no
- CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.

Do this now: Federal remediation deadline 2024-06-13; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 29, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2020-17519

Published: 2024-05-23
Last revised: 2024-05-23
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

2024-05-23 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 7.5; EPSS first scored at 97.9%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2024-06-13 (past due).

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Official fix for CVE-2020-17519

Check the vendor's security advisory channel for the patched Flink versions and workarounds.

CISA KEV entry

Common questions about CVE-2020-17519

Is CVE-2020-17519 actively exploited?

Yes. CVE-2020-17519 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2024-05-23, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 98%.

What is the CISA deadline and required action for CVE-2020-17519?

CISA set the federal (BOD 22-01) remediation due date at 2024-06-13, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What fixes CVE-2020-17519?

Check the vendor's security advisory for the patched Flink versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2020-17519?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2020-17519's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

More exploited Apache CVEs: CVE-2026-34486 CVE-2026-34197 CVE-2024-38475 CVE-2025-24813 CVE-2024-45195 CVE-2024-27348 CVE-2024-38856 CVE-2024-32113
All Apache exploited CVEs on one page: Apache vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.