CVE-2023-5156Network attack vector

Application crash via getaddrinfo error-path memory leak

Published Sep 25, 2023 · Updated Dec 18, 2025

Memory leak in getaddrinfo in GNU C Library 2.34 through 2.38 allows remote attackers to crash applications via repeated lookups. The free_and_return path uses piecemeal frees instead of gaih_result_reset, leaving allocations owned by gaih_result unreleased after a failed lookup. Exposure requires repeated attacker-influenced getaddrinfo calls; resulting memory exhaustion can terminate the calling application.

CVSS severity7.5
High
EPSS probability1.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in getaddrinfo in GNU C Library 2.34 through 2.38 allows remote attackers to crash applications via repeated lookups. The free_and_return path uses piecemeal frees instead of gaih_result_reset, leaving allocations owned by gaih_result unreleased after a failed lookup. Exposure requires repeated attacker-influenced getaddrinfo calls; resulting memory exhaustion can terminate the calling application.

The record

CVE
CVE-2023-5156
Published
Sep 25, 2023
Updated
Dec 18, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-401, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5Red Hat, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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