CVE-2018-16840

curl: Use-after-free when closing "easy" handle in Curl_close()

Published Oct 31, 2018 CVSS 3.1 · 9.8 Critical EPSS 3.4% KEV · Not listed
Description
A heap use-after-free flaw was found in curl versions from 7.59.0 through 7.61.1 in the code related to closing an easy handle. When closing and cleaning up an 'easy' handle in the `Curl_close()` function, the library code first frees a struct (without nulling the pointer) and might then subsequently erroneously write to a struct field within that already freed struct.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2018-8636 A heap use-after-free flaw was found in curl versions from 7.59.0 through 7.61.1 in the code related to closing an easy handle. When closing and cleaning up an 'easy' handle in the `Curl_close()` function, the library code first frees a struct (without nulling the pointer) and might then subsequently erroneously write to a struct field within that already freed struct.
Ubuntu USN Ubuntu USN USN-3805-1 curl vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Apr 16, 2026, 2:08 PM
Reserved
Sep 11, 2018, 12:00 AM
Status
Analyzed
Published
Oct 31, 2018, 6:29 PM
Modified
Jun 17, 2026, 1:44 AM
Severity
Low
Public date
Oct 31, 2018, 12:00 AM