Security Resilience

CWE · MITRE source

CWE-244Improper Clearing of Heap Memory Before Release ('Heap Inspection')

Abstraction: Variant · CVEs in our corpus: 21

Using realloc() to resize buffers that store sensitive information can leave the sensitive information exposed to attack, because it is not removed from memory.

When sensitive data such as a password or an encryption key is not removed from memory, it could be exposed to an attacker using a "heap inspection" attack that reads the sensitive data using memory dumps or other methods. The realloc() function is commonly used to increase the size of a block of allocated memory. This operation often requires copying the contents of the old memory block into a new and larger block. This operation leaves the contents of the original block intact but inaccessible to the program, preventing the program from being able to scrub sensitive data from memory. If an attacker can later examine the contents of a memory dump, the sensitive data could be exposed.

Last updated: 15 October 2026 14:21 UTC

Control responseHuman-reviewed

Answering this weakness across the control lifecycle, from our framework cross-walks.

Prevent
Stop it (NIST 800-53 / CSF Protect)
  • SC-4 Information in Shared System Resources
  • SI-12 Information Management and Retention
  • PR.DS-10
  • SC-4 Information in Shared System Resources
Detect
Catch it (CSF Detect / Respond)

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Harden
Shrink the surface (DISA STIG)

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Validate
Prove the fix (OWASP ASVS)

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NIST 800-53 r5 controls PROPOSED for this weakness (2)AI-assisted

These are model PROPOSALS, not graded mappings. They come from controls_to_cwe_proposals, which carries no grade field at all; across the CWE pages 1,540 of 1,722 such associations (89%) have never been graded by anything. The heading said “address” until 2026-09-29, which asserted a relationship the data does not carry. Graded cross-walks are on the framework map, not here.

Control Title Family Why it addresses this CWE
SC-4Information in Shared System ResourcesSCgraded mostly Forces clearing of heap memory contents prior to release, preventing subsequent processes from inspecting prior sensitive data.
SI-12Information Management and RetentionSIInformation management requirements drive clearing of sensitive contents from memory prior to release or reuse.

Top CVEs of this weakness type, ranked by Risk Priority

CVE Risk CVSS EPSS Published
CVE-2026-20349 KEV 8.88.60.01012026-08-11
CVE-2025-26304 6.28.20.00392025-02-20
CVE-2025-26305 6.28.20.00392025-02-20
CVE-2026-20039 6.28.60.00372026-03-04
CVE-2025-36118 5.87.50.00362025-11-17
CVE-2025-70873 5.87.50.00332026-03-12
CVE-2025-5105 5.77.30.00452025-05-23
CVE-2025-456635.16.50.00372025-11-03
CVE-2022-20922 4.75.80.00822022-11-15
CVE-2022-20943 4.75.80.00952022-11-15
CVE-2025-17194.75.90.00392026-01-20
CVE-2025-17224.75.90.00392026-01-20
CVE-2025-33013 4.66.20.00142025-07-24
CVE-2025-1759 4.65.90.00332025-08-18
CVE-2025-36083 4.66.20.00132025-10-28
CVE-2025-1721 4.65.90.00332025-12-26
CVE-2025-331014.55.90.00242026-02-17
CVE-2023-20177 3.44.00.00532023-11-01
CVE-2023-20070 3.44.00.00542023-11-01
CVE-2023-20031 3.24.00.00282023-11-01