CVE-2008-3843

What it is

Request Validation (aka the ValidateRequest filters) in ASP.NET in Microsoft .NET Framework with the MS07-040 update does not properly detect dangerous client input, which allows remote attackers to conduct cross-site scripting (XSS) attacks, as demonstrated by a query string containing a "<~/" (less-than tilde slash) sequence followed by a crafted STYLE element.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

22.0% chance of exploitation in the next 30 days (EPSS). Higher than most.

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2008-08-27 20:41 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-16 22:56 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 22.0% in the next 30 days (EPSS).
• Severity: 4.3 MEDIUM (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2008-08-27 20:41 UTC

Last modified

2026-06-16 22:56 UTC

Exploit probability

22.0% · EPSS, next 30 days

Weakness

CWE-79 · Cross-site scripting

Record status

Modified

Affected

• Microsoft .net Framework 1.0
• Microsoft .net Framework 1.1
• Microsoft .net Framework 2.0

Attack profile CVSS 2.0 · 4.3

Attack vector

Network

Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

None

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-2008-3843.md and follow it. Check whether this project is affected by CVE-2008-3843. 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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