CVE-2024-3209: A vulnerability was found in UPX up to 4.2.2

Q: How do I fix CVE-2024-3209?

upx: upgrade to newer than 4.2.2; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2024-3209 being exploited?

CVE-2024-3209 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2024-3209 affect?

CVE-2024-3209 affects upx, fedora. Severity is medium (CVSS 5.5). A vulnerability was found in UPX up to 4.2.2. It has been rated as critical. This issue affects the function get_ne64 of the file bele.h. The manipulation leads to heap-based buffer overflow. The exploit has been disclosed to the public and

Q: How urgent is CVE-2024-3209?

Priority 41/100. Public exploit reference

This month

MEDIUM 5.5UPGRADEMITIGATE

CVE-2024-3209 is a medium-severity flaw (CVSS 5.5) affecting upx, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability was found in UPX up to 4.2.2. It has been rated as critical. This issue affects the function get_ne64 of the file bele.h. The manipulation leads to heap-based buffer overflow. The exploit has been disclosed to the public and may be used. The associated identifier of this vulnerability is VDB-259055. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.2% (top 31%)
CISA exploited list	No
Weakness	CWE-122
Published	2024-04-02
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: fedoraproject · upx

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

Am I affected?

Timeline

2024-04-02 23:15 UTCPublished CVE record published
2026-06-17 07:43 UTCUpdated Record last modified

upx upx UPGRADE

Affected: <= 4.2.2

Fixed in: newer than 4.2.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy upx || rpm -q upx || upx --version

2. UPGRADE to newer than 4.2.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade upx

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade upx

Note

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

fedoraproject fedora MITIGATE

Affected: 38 · 39 · 40

Fixed in: no fixed release known

Safe to downgrade to: a release before 38

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.

Verify at the official source NVD · CVE Program · 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-2024-3209?

upx: upgrade to newer than 4.2.2; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2024-3209 being exploited?

CVE-2024-3209 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-3209 affect?

CVE-2024-3209 affects upx, fedora. Severity is medium (CVSS 5.5). A vulnerability was found in UPX up to 4.2.2. It has been rated as critical. This issue affects the function get_ne64 of the file bele.h. The manipulation leads to heap-based buffer overflow. The exploit has been disclosed to the public and

How urgent is CVE-2024-3209?

Priority 41/100. Public exploit reference

Related CVEs

CVE-2025-2849 LOW 3.3 UPGRADE A vulnerability, which was classified as problematic, was found in UPX up to 5.0.0

References

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