How severe is CVE-2018-4878?

CVE-2018-4878 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which products are affected by CVE-2018-4878?

Affected package information for CVE-2018-4878 is not yet fully mapped. Check the official advisory links for details.

How do I patch CVE-2018-4878?

Apply the adobe flash player security patch or hotfix for CVE-2018-4878 on the affected version, following the vendor advisory for your exact build.

How do I detect CVE-2018-4878 across my infrastructure?

Inventory every adobe flash player deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

How do I mitigate CVE-2018-4878 if there is no patch (or I can't update yet)?

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2018-4878?

O3 detects and blocks CVE-2018-4878 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Is CVE-2018-4878 actively exploited in the wild?

Yes. There are 16 known exploit references for CVE-2018-4878, including 3 documented proof-of-concept exploits on Exploit-DB and 9 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2018-4878?

CVE-2018-4878 has an EPSS (Exploit Prediction Scoring System) score of 89.5%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2018-4878 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2018-4878 (Adobe Flash Player Use-After-Free Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: The impacted product is end-of-life and should be disconnected if still in use. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2018-4878?

CVE-2018-4878 is classified as Use After Free (CWE-416). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2018-4878?

CVE-2018-4878 affects adobe flash player; redhat enterprise linux desktop (1 version, e.g. 6.0); redhat enterprise linux server (1 version, e.g. 6.0); redhat enterprise linux workstation (1 version, e.g. 6.0). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2018-4878 published, and has it been updated?

CVE-2018-4878 was published on February 6, 2018 and was last updated on June 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2021-11-03 — agencies required to remediate by 2022-05-03 · Ransomware

CVE-2018-4878

HIGH

A use-after-free vulnerability was discovered in Adobe Flash Player before 28.0.0.161. This vulnerability occurs due to a dangling pointer in the Primetime SDK related to media player…

Published

Feb 6, 2018

Updated

Jun 17, 2026

Affected

0 pkgs

Patched

None yet

Exploits

16 known

EPSS Exploitation Probability

via FIRST.org ↗

89.5%probability of exploitation in next 30 days

Very High Risk100th percentile-0.09%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

A use-after-free vulnerability was discovered in Adobe Flash Player before 28.0.0.161. This vulnerability occurs due to a dangling pointer in the Primetime SDK related to media player handling of listener objects. A successful attack can lead to arbitrary code execution. This was exploited in the wild in January and February 2018.

Affected Products

4 products · 7 configurations

Application

flash playeradobe

< 28.0.0.161

range

enterprise linux desktopredhat

1 version

6.0

enterprise linux serverredhat

1 version

6.0

enterprise linux workstationredhat

1 version

6.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-44745localwindows

Flash ActiveX 28.0.0.137 - Code Execution (2)

by smgorelik · Feb 13, 2016

Exploit-DB Source

EDB-44412remotemultiple

Adobe Flash < 28.0.0.161 - Use-After-Free

by SyFi · Apr 6, 2018

Exploit-DB Source

EDB-44744localwindows

Flash ActiveX 28.0.0.137 - Code Execution (1)

by smgorelik · Feb 16, 2016

Exploit-DB Source

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every adobe flash player deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the adobe flash player security patch or hotfix for CVE-2018-4878 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2018-4878 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2018-4878. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Runtime Protection

Is CVE-2018-4878 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2018-4878 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

Protect my workloads How runtime protection works

CVE-2018-4878

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

How O3 protects you

Frequently Asked Questions

Is CVE-2018-4878 being exploited in your environment?