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Vulnerability details: VCID-ke81-x2ze-rbc5
Vulnerability ID VCID-ke81-x2ze-rbc5
Aliases CVE-2023-27537
Summary Double Free A double free vulnerability exists in libcurl <8.0.0 when sharing HSTS data between separate "handles". This sharing was introduced without considerations for do this sharing across separate threads but there was no indication of this fact in the documentation. Due to missing mutexes or thread locks, two threads sharing the same HSTS data could end up doing a double-free or use-after-free.
Status Published
Exploitability 0.5
Weighted Severity 5.0
Risk 2.5
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-415 Double Free
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3 5.6 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-27537.json
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
epss 0.00061 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
epss 0.00083 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
epss 0.00083 https://api.first.org/data/v1/epss?cve=CVE-2023-27537
cvssv3.1 Low https://curl.se/docs/CVE-2023-27537.html
cvssv3.1 5.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-27537.json
https://api.first.org/data/v1/epss?cve=CVE-2023-27537
https://curl.se/docs/CVE-2023-27537.html
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://hackerone.com/reports/1897203
2179097 https://bugzilla.redhat.com/show_bug.cgi?id=2179097
CVE-2023-27537 https://nvd.nist.gov/vuln/detail/CVE-2023-27537
GLSA-202310-12 https://security.gentoo.org/glsa/202310-12
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-27537.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.14539
EPSS Score 0.00047
Published At April 2, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:51:04.975757+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/conan/libcurl/CVE-2023-27537.yml 38.0.0