CVE-2018-4878: Adobe Flash Player Use-After-Free Vulnerability

Q: How do I fix CVE-2018-4878?

flash player: upgrade to 28.0.0.161; enterprise linux desktop: mitigate or apply the listed mitigation; enterprise linux server: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2018-4878 being exploited?

Yes. CVE-2018-4878 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2018-4878 affect?

CVE-2018-4878 affects flash player, enterprise linux desktop, enterprise linux server. Severity is high (CVSS 7.8). 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 le

Q: How urgent is CVE-2018-4878?

Priority 92/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; On your watchlist

Patch now

HIGH 7.8EXPLOITEDWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2018-4878 is a high-severity flaw (CVSS 7.8) affecting flash player, enterprise linux desktop, enterprise linux server, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Used in ransomware campaigns
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	90.3% (top 1%)
CISA exploited list	Yes, fix due 2022-05-03, used in ransomware
Weakness	CWE-416
Published	2018-02-06
Last modified	2026-06-17

Publisher (CNA): Adobe Systems Incorporated · Vendor: adobe · redhat

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-02-06 21:29 UTCPublished CVE record published
2021-11-03Exploited Added to the CISA Known Exploited Vulnerabilities list
2022-05-03Deadline CISA due date for US federal agencies to patch
2026-06-17 01:59 UTCUpdated Record last modified

adobe flash player UPGRADE

Affected: < 28.0.0.161

Fixed in: 28.0.0.161

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy flash-player || rpm -q flash-player || flash-player --version

2. UPGRADE to 28.0.0.161 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade flash-player

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade flash-player

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

redhat enterprise linux desktop MITIGATE

Affected: 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux server MITIGATE

Affected: 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux workstation MITIGATE

Affected: 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

adobe flash player UPGRADE

Affected: < 28.0.0.161

Fixed in: 28.0.0.161

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy flash-player || rpm -q flash-player || flash-player --version

2. UPGRADE to 28.0.0.161 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade flash-player

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade flash-player

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

adobe flash player UPGRADE

Affected: < 28.0.0.161

Fixed in: 28.0.0.161

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy flash-player || rpm -q flash-player || flash-player --version

2. UPGRADE to 28.0.0.161 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade flash-player

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade flash-player

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · shotcut · FIXED · 26.10.30-1.fc46 · FEDORA-2026-7787c7fc2d · source

sudo dnf upgrade --advisory=FEDORA-2026-7787c7fc2d

RHEL 6 Supplementary · flash-plugin · FIXED · flash-plugin-28.0.0.161-1.el6_9

sudo dnf upgrade --advisory=RHSA-2018:0285 rpm -q flash-plugin

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: vysecurity/CVE-2018-4878 (86 stars)
GitHub PoC: SyFi/CVE-2018-4878 (7 stars)
GitHub PoC: B0fH/CVE-2018-4878 (2 stars)
Write-up: blog.morphisec.com/flash-exploit-cve-2018-4878-spotted-in-the-wild-massive-malspam-campaig
Write-up: github.com/InQuest/malware-samples/tree/master/CVE-2018-4878-Adobe-Flash-DRM-UAF-0day
Exploit-DB: Adobe Flash < 28.0.0.161 - Use-After-Free
Exploit-DB: Flash ActiveX 28.0.0.137 - Code Execution (1)
Exploit-DB: Flash ActiveX 28.0.0.137 - Code Execution (2)

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-4878?

flash player: upgrade to 28.0.0.161; enterprise linux desktop: mitigate or apply the listed mitigation; enterprise linux server: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-4878 being exploited?

Yes. CVE-2018-4878 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2018-4878 affect?

CVE-2018-4878 affects flash player, enterprise linux desktop, enterprise linux server. Severity is high (CVSS 7.8). 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 le

How urgent is CVE-2018-4878?

Priority 92/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; On your watchlist

Software pages

Adobe Flash vulnerabilities

Related CVEs

CVE-2018-15982 HIGH 7.8 EXPLOITED UPGRADE UPGRADE Adobe Flash Player Use-After-Free Vulnerability
CVE-2020-9746 HIGH 7.0 UPGRADE UPGRADE Adobe Flash Player version 32.0.0.433 (and earlier) are affected by an exploitable NULL pointer dereference vu
CVE-2020-9633 CRITICAL 9.8 UPGRADE UPGRADE Adobe Flash Player Desktop Runtime 32.0.0.371 and earlier, Adobe Flash Player for Google Chrome 32.0.0.371 and
CVE-2020-3757 HIGH 8.8 UPGRADE UPGRADE Adobe Flash Player versions 32.0.0.321 and earlier, 32.0.0.314 and earlier, 32.0.0.321 and earlier, and 32.0.0
CVE-2019-8075 HIGH 7.5 UPGRADE UPGRADE Adobe Flash Player version 32.0.0.192 and earlier versions have a Same Origin Policy Bypass vulnerability

References

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