How severe is CVE-2002-0840?

No CVSS score has been assigned to CVE-2002-0840 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2002-0840?

Affected package information for CVE-2002-0840 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2002-0840?

No fixed release is recorded for CVE-2002-0840 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2002-0840 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2002-0840 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2002-0840 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2002-0840, including 1 documented proof-of-concept exploit on Exploit-DB. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2002-0840?

CVE-2002-0840 has an EPSS (Exploit Prediction Scoring System) score of 95.1%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

When was CVE-2002-0840 published, and has it been updated?

CVE-2002-0840 was published on October 11, 2002 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

Not in CISA KEV

CVE-2002-0840 — Red Hat

CVE-2002-0840 is a security vulnerability. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.

Published

Oct 11, 2002

Updated

Apr 10, 2026

Affected

5 products

Patched

See advisory

Exploits

1 known

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

95.1%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

Cross-site scripting (XSS) vulnerability in the default error page of Apache 2.0 before 2.0.43, and 1.3.x up to 1.3.26, when UseCanonicalName is "Off" and support for wildcard DNS is present, allows remote attackers to execute script as other web page visitors via the Host: header, a different vulnerability than CAN-2002-1157.

Affected Products

5 products · 47 configurations

Application

http serverapache

29 versions

1.31.3.11.3.31.3.41.3.61.3.91.3.111.3.121.3.141.3.171.3.181.3.19

Application

application serveroracle

5 versions

1.0.21.0.2.1s1.0.2.29.0.29.0.2.1

Application

database serveroracle

3 versions

8.1.79.2.19.2.2

Application

oracle8ioracle

4 versions

8.1.78.1.7_.0.0_enterprise8.1.7_.1.0_enterprise8.1.7.1

Application

oracle9ioracle

5 versions

9.09.0.19.0.1.29.0.1.39.0.2

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-21885remotemultiple✓ Verified

Apache 1.3/2.0.x - Server Side Include Cross-Site Scripting

by mattmurphy · Oct 2, 2002

Exploit-DB Source

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2002-0840 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatLow

RHSA-2002:251Red Hat Enterprise Linux AS (Advanced Server) version 2.1 RHSA-2002:222Red Hat Linux 6.2 RHSA-2003:106Red Hat Linux 7.1 RHSA-2002:243Red Hat Stronghold 3 RHSA-2002:244Red Hat Stronghold 4 RHSA-2002:248Stronghold 4 for Red Hat Enterprise Linux

Frequently Asked Questions

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CVE-2002-0840 — Red Hat

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2002-0840 in your dependencies?