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Variant weakness

Draft

CWE-239: Failure to Handle Incomplete Element

The product does not properly handle when a particular element is not completely specified.

Last updated May 1, 2026

3

Recorded CVEs

With this primary weakness

0

KEVs

In the CISA KEV catalog

Not rated

Likelihood of exploit

Per MITRE

Variant

Abstraction

MITRE classification

Overview

CWE-239 (Failure to Handle Incomplete Element) is a variant-level software weakness catalogued by MITRE in the Common Weakness Enumeration (CWE). It describes a recurring type of mistake that can lead to exploitable security vulnerabilities.

Real-world CVEs

3 recorded CVEs are caused by CWE-239 (Failure to Handle Incomplete Element). The highest-severity and most recent are shown first. 0 new CWE-239 CVEs have been recorded so far in 2026 (1 in 2025).

Common consequences

What can happen when CWE-239 is exploited.

Varies by Context, Unexpected State

Affects: Integrity, Other

How it happens

When it is introduced

Typically introduced during these phases of the software lifecycle.

Implementation

Illustrative examples

Real CVEs that MITRE cites as examples of this weakness.

CVE-2002-1532 — HTTP GET without \r\n\r\n CRLF sequences causes product to wait indefinitely and prevents other users from accessing it.
CVE-2003-0195 — Partial request is not timed out.
CVE-2005-2526 — MFV. CPU exhaustion in printer via partial printing request then early termination of connection.
CVE-2002-1906 — CPU consumption by sending incomplete HTTP requests and leaving the connections open.

Terminology & mappings

Mapped taxonomies

PLOVER: Incomplete Element

Frequently asked questions

Common questions about CWE-239.

What is CWE-239?

The product does not properly handle when a particular element is not completely specified.

What CVEs are caused by CWE-239?

3 recorded CVEs are attributed to CWE-239, including CVE-2020-10280, CVE-2025-41724, CVE-2024-29155.

What are the consequences of CWE-239?

Exploiting CWE-239 can lead to: Varies by Context, Unexpected State.

Is CWE-239 actively exploited?

3 recorded CVEs are caused by CWE-239; none are currently in CISA's KEV catalog of actively exploited flaws.

References

Weakness data is sourced from the MITRE CWE catalog (v4.20). CVE associations are aggregated and kept current by RadicalNotion.AI.

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