Exploited CVEs / Oracle / CVE-2015-4852

CVE-2015-4852

Oracle WebLogic Server Deserialization of Untrusted Data Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2022-05-03 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Oracle Critical Patch Updates, linked below.

Risk summary

CriticalCISA KEV

9.8

CVSS base

96%

EPSS exploit probability

Critical

Severity

2021-11-03

Added to KEV

2022-05-03 (past due)

CISA due date

Actively exploited Oracle WebLogic Server vulnerability, Critical severity, CVSS 9.8. Added to the CISA KEV catalog 2021-11-03.

Senserva AI read on CVE-2015-4852 CISA required action Official fix for CVE-2015-4852 Admin questions

Senserva AI Opinion for CVE-2015-4852

This is the original T3/RMI Apache Commons Collections deserialization flaw in Oracle WebLogic Server, giving unauthenticated remote code execution over the WebLogic listen port. Any internet-facing WebLogic instance is exposed, and with a 96 percent EPSS score plus confirmed exploitation in CISA KEV since 2021, working exploit chains are widely available. Despite being from 2015 it remains a favorite for initial access because unpatched WebLogic servers are still common.

Do this: Apply Oracle's critical patch update for WebLogic and, if you cannot patch immediately, block or filter access to the T3 protocol on the WebLogic listen ports.

AI-generated from public data, 2026-07-27. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2015-4852

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

I run IT security. Facts for CVE-2015-4852, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2015-4852.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2015-4852: Oracle WebLogic Server Deserialization of Untrusted Data Vulnerability
- Affected: Oracle WebLogic Server
- Severity: Critical, CVSS 9.8; EPSS 30-day exploitation probability 96%
- Added to CISA KEV: 2021-11-03; federal remediation due 2022-05-03
- Ransomware-linked: no
- CISA required action: Apply updates per vendor instructions.
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.

The fix ships from the vendor: Oracle Critical Patch Updates.

Do this now: Federal remediation deadline 2022-05-03; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 14, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2015-4852

Published: 2021-11-03
Last revised: 2021-11-03
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

2021-11-03 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 9.8; EPSS first scored at 96.0%

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: 2022-05-03 (past due).

Apply updates per vendor instructions.

Official fix for CVE-2015-4852

The authoritative fix and affected-version list are published by the vendor. Find the WebLogic Server advisory on Oracle Critical Patch Updates.

Oracle Critical Patch Updates CISA KEV entry

Common questions about CVE-2015-4852

Is CVE-2015-4852 actively exploited?

Yes. CVE-2015-4852 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 96%.

What is the CISA deadline and required action for CVE-2015-4852?

CISA set the federal (BOD 22-01) remediation due date at 2022-05-03, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.

What fixes CVE-2015-4852?

The authoritative fix is in the vendor advisory: see Oracle Critical Patch Updates for the patched WebLogic Server 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-2015-4852?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2015-4852'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

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All Oracle exploited CVEs on one page: Oracle 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.