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 version has been published for CVE-2002-0840 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

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 90.2%, 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.

CVE-2002-0840: Cross-Site Scripting

EPSS Exploitation Probability

via FIRST.org ↗

90.2%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

Is CVE-2002-0840 in your stack?

O3 detects CVE-2002-0840 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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