How severe is CVE-2008-3842?

CVE-2008-3842 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2008-3842 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2008-3842?

CVE-2008-3842 primarily affects Microsoft .net Framework. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2008-3842?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2008-3842 published?

CVE-2008-3842 was published on 2008-08-27 and last updated on 2026-06-16.

CVE-2008-3842

CVE-2008-3842 is a medium-severity vulnerability in Microsoft .net Framework with a CVSS 2.0 base score of 4.3. Its EPSS exploit-prediction score of 20% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 20% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Microsoft .net Framework
Published: 2008-08-27
Last modified: 2026-06-16

Description

Request Validation (aka the ValidateRequest filters) in ASP.NET in Microsoft .NET Framework without 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 slash) sequence.

Frequently asked questions

What is CVE-2008-3842?: Request Validation (aka the ValidateRequest filters) in ASP.NET in Microsoft .NET Framework without 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 slash) sequence.
How severe is CVE-2008-3842?: CVE-2008-3842 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2008-3842 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2008-3842?: CVE-2008-3842 primarily affects Microsoft .net Framework. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2008-3842?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2008-3842 published?: CVE-2008-3842 was published on 2008-08-27 and last updated on 2026-06-16.

References

Affected products (3)

cpe:2.3:a:microsoft:.net_framework:2.0:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:1.1:sp1:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:1.0:sp3:*:*:*:*:*:*

More vulnerabilities in Microsoft .net Framework

CVE-2014-4121 — Critical (CVSS 10.0): Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 does not properly parse internationalized…
CVE-2014-4073 — Critical (CVSS 10.0): Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 processes unverified data during interaction…
CVE-2014-1806 — Critical (CVSS 10.0): The .NET Remoting implementation in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5, 3.5.1, 4, 4.5, and 4.5.1 does not…
CVE-2013-0073 — Critical (CVSS 10.0): The Windows Forms (aka WinForms) component in Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, and 4.5 does not…
CVE-2008-5100 — Critical (CVSS 10.0): The strong name (SN) implementation in Microsoft .NET Framework 2.0.50727 relies on the digital signature Public Key…
CVE-2002-0369 — Critical (CVSS 10.0): Buffer overflow in ASP.NET Worker Process allows remote attackers to cause a denial of service (restart) and possibly…

All CVEs affecting Microsoft .net Framework →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →