CVE-2009-1096

What it is

Buffer overflow in unpack200 in Java SE Development Kit (JDK) and Java Runtime Environment (JRE) 5.0 Update 17 and earlier, and 6 Update 12 and earlier, allows remote attackers to access files or execute arbitrary code via a JAR file with crafted Pack200 headers.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

8.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2009-03-25 00:00 UTC ReservedThe CVE id was reserved by its CNA
2. 2009-03-25 23:30 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-06-16 23:06 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 8.2% in the next 30 days (EPSS).
• Severity: 10.0 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2009-03-25 23:30 UTC

Last modified

2026-06-16 23:06 UTC

Exploit probability

8.2% · EPSS, next 30 days

Weakness

CWE-119 · Buffer errors

Record status

Modified

Affected

• Sun Jdk ≤ 1.5.0
• Sun Jdk 1.5.0
• Sun Jre ≤ 1.5.0
• Sun Jre 1.5.0
• Sun Jdk ≤ 1.6.0
• Sun Jdk 1.6.0
• Sun Jre ≤ 1.6.0
• Sun Jre 1.6.0

Attack profile CVSS 2.0 · 10.0

Attack vector

Network

Complexity

Low

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2009-1096.md and follow it. Check whether this project is affected by CVE-2009-1096. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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