CVE-2018-16840

highpriority · track · 40EPSS 0.034 · 89 %ileDEEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

3.40% (89th) EPSS

CVSS 7.5 · high

Is it mine?

19 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · cert_bund · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 4.3–9.8

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.04.3mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:Nsecondary · ENISA EU

v3.04.3mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:Nsecondary · secalert@redhat.com USexploitability 2.8 · impact 1.4

v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-416USprimary

affected products (19)

Products and version ranges known to be affected.

Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Dell Avamar <19.12all versionscert_bundDE
Dell NetWorker <19.9.0.1all versionscert_bundDE
Gentoo Linuxall versionscert_bundDEcpe:/o:gentoo:linux:-
Open Source cURL <7.62.0all versionscert_bundDE
Open Source libcurl <7.62.0all versionscert_bundDE
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Dell Avamar< 19.12cert_bundDE
Dell Networker< 19.9.0.1cert_bundDE
Open Source cURL< 7.62.0cert_bundDE
Open Source libcurl< 7.62.0cert_bundDE
The Curl Project curl≤ from 7.59.0 to 7.61.1enisa_euvdEU
canonical ubuntu linux= 14.04nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
canonical ubuntu linux= 16.04nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
canonical ubuntu linux= 18.04nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
canonical ubuntu linux= 18.10nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
haxx curl7.59.0 → 7.62.0nvdUScpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-1641cURL: Mehrere SchwachstellenDeutsch2018-10-30csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in cURL und libcurl ausnutzen, um Informationen offenzulegen, einen Denial of Service Zustand herbeizuführen und um einen nicht näher spezifizierten Angriff durchzuführen.
CURL-CVE-2018-16840use after free in handle close2018-10-31vendor · osvUS
libcurl contains a heap use after free flaw in 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 clearing the pointer) and might then subsequently erroneously write to a struct field within that already freed struct.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund nvd osv NVD CVE.org MITRE

published 2018-10-31modified 2026-06-17

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+12246 more

references (28)

External citations — patches, advisories, analysis.

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