What is CVE-2010-0840?A critical-severity flaw criminals are using now.
CVE-2010-0840 is a critical-severity flaw (CVSS 9.8) in JRE from Oracle, published on 1 April 2010. It is on the list of flaws known to be exploited, so criminals are already using it. The latest forecast puts its chance of use in the next 30 days at 96%. If you run an affected version, patch it first.
Published 1 April 2010. Record last updated 22 October 2025. We keep this page's data up to date.
What is CVE-2010-0840? In plain terms.
It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.
Unspecified vulnerability in the Java Runtime Environment component in Oracle Java SE and Java for Business 6 Update 18, 5.0 Update 23, and 1.4.2_25 allows remote attackers to affect confidentiality, integrity, and availability via unknown vectors. NOTE: the previous information was obtained from the March 2010 CPU. Oracle has not commented on claims from a reliable researcher that this is related to improper checks when executing privileged methods in the Java Runtime Environment (JRE), which allows attackers to execute arbitrary code via (1) an untrusted object that extends the trusted class but has not modified a certain method, or (2) "a similar trust issue with interfaces," aka "Trusted Methods Chaining Remote Code Execution Vulnerability."
What kind of flaw is it?
- UnknownUnknown
How an attack on it works
Read straight from its severity rating, translated out of the shorthand.
- Where an attacker can beAnywhere on the internet
- How hard it is to pull offEasy: no special conditions
- Login needed firstNo login needed
- Does someone have to clickNo, nobody has to do anything
- What an attacker getsCan read data, change data and take it offline
Severity vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Is CVE-2010-0840 being exploited? Yes.
Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 96%.
Timeline
- Published
- Record last updated
CVE-2010-0840 scores 86. Action: Emergency patch.
We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:
- Evidence it is being exploitedBiggest factor
- How severe it isStrong factor
- How widely exposed it isSmaller factor
- Threat activity around itSmaller factor
85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.
When CVE-2010-0840 matches software you track, it lands in your list with its score and the reasons behind it.
See your own ranked list →Who is affected by CVE-2010-0840? 3 products.
The published record lists 3 products from 3 vendors. If you run one of these, check your version, then go to the fix below.
How do I fix CVE-2010-0840? Four steps.
- Check whether you run itCompare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
- Apply the vendor’s fixInstall the latest update from the vendor. The references list where the vendor has published details.
- If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
- Check it wasn’t used before you patchedBecause criminals are already using this flaw, look for signs of a break-in on affected systems using the vendor’s guidance.
Does CVE-2010-0840 affect you? We'll keep checking.
Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.
- Tell us what you runPick your software from a list, or let us work it out from your website.
- We match it to every flawOver 400,000 published flaws, checked against your list.
- Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
- Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
Free plan, no card needed. Nothing to install.
1 flaw being exploited affects software Acme tracks
Unspecified vulnerability in the Java Runtime Environment component in Oracle Java SE and Java for Business 6 Update 18, 5.0 Update 23, and 1.4.2_25 allows r...
- Matched to
- JRE on Acme's software list
- What to do
- Patch first, then check for signs of use
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
CVE-2010-0840 is a critical-severity flaw in JRE from Oracle, published on 1 April 2010. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.
It scores 9.8 out of 10 on the CVSS severity scale, which is critical. Our risk score for CVE-2010-0840 is 86 out of 100, which is Critical. Its action is "Emergency patch". Attackers are using this flaw today. If you run an affected version, it goes to the top of your list.
Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 96%.
For JRE from Oracle: 1.4.2_25, 1.5.0-update23, 1.6.0-update18. The record lists 3 products in all, each with its versions, under "Who is affected" on this page.
Install the update the vendor names in its advisory. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. Because criminals are already using it, also check affected systems for signs of a break-in.