curl: Re-using connection with wrong client cert
Published Aug 10, 2016
7.5
HIGHCVSS 3.0
EPSS 15.36%
Description
curl and libcurl before 7.50.1 do not check the client certificate when choosing the TLS connection to reuse, which might allow remote attackers to hijack the authentication of the connection by leveraging a previously created connection with a different client certificate.
Affected products
No data.
No data.
Red Hat Enterprise Linux 7
curl-0:7.29.0-35.el7
Fixed · RHSA-2016:2575
Red Hat JBoss Core Services
n/a
Fixed · RHSA-2016:2957
Red Hat Software Collections for Red Hat Enterprise Linux 6
httpd24-curl-0:7.61.1-1.el6
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 6
httpd24-httpd-0:2.4.34-7.el6
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 6
httpd24-nghttp2-0:1.7.1-7.el6
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7
httpd24-curl-0:7.61.1-1.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7
httpd24-httpd-0:2.4.34-7.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7
httpd24-nghttp2-0:1.7.1-7.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS
httpd24-curl-0:7.61.1-1.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS
httpd24-httpd-0:2.4.34-7.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS
httpd24-nghttp2-0:1.7.1-7.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS
httpd24-curl-0:7.61.1-1.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS
httpd24-httpd-0:2.4.34-7.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS
httpd24-nghttp2-0:1.7.1-7.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS
httpd24-curl-0:7.61.1-1.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS
httpd24-httpd-0:2.4.34-7.el7
Fixed · RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS
httpd24-nghttp2-0:1.7.1-7.el7
Fixed · RHSA-2018:3558
.NET Core 1.0 on Red Hat Enterprise Linux
rh-dotnetcore10-curl
Out of support scope
.NET Core 1.1 on Red Hat Enterprise Linux
rh-dotnetcore11-curl
Out of support scope
.NET Core 2.0 on Red Hat Enterprise Linux
rh-dotnet20-curl
Out of support scope
.NET Core 2.1 on Red Hat Enterprise Linux
rh-dotnet21-curl
Will not fix
Red Hat Enterprise Linux 5
curl
Will not fix
Red Hat Enterprise Linux 6
curl
Will not fix
Red Hat Enterprise Virtualization 3
mingw-virt-viewer
Will not fix
Red Hat JBoss Enterprise Web Server 3
curl
Affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | curl-0:7.29.0-35.el7 | Fixed | RHSA-2016:2575 |
| Red Hat JBoss Core Services | n/a | Fixed | RHSA-2016:2957 |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | httpd24-curl-0:7.61.1-1.el6 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | httpd24-httpd-0:2.4.34-7.el6 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | httpd24-nghttp2-0:1.7.1-7.el6 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | httpd24-curl-0:7.61.1-1.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | httpd24-httpd-0:2.4.34-7.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | httpd24-nghttp2-0:1.7.1-7.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | httpd24-curl-0:7.61.1-1.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | httpd24-httpd-0:2.4.34-7.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | httpd24-nghttp2-0:1.7.1-7.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | httpd24-curl-0:7.61.1-1.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | httpd24-httpd-0:2.4.34-7.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | httpd24-nghttp2-0:1.7.1-7.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | httpd24-curl-0:7.61.1-1.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | httpd24-httpd-0:2.4.34-7.el7 | Fixed | RHSA-2018:3558 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | httpd24-nghttp2-0:1.7.1-7.el7 | Fixed | RHSA-2018:3558 |
| .NET Core 1.0 on Red Hat Enterprise Linux | rh-dotnetcore10-curl | Out of support scope | n/a |
| .NET Core 1.1 on Red Hat Enterprise Linux | rh-dotnetcore11-curl | Out of support scope | n/a |
| .NET Core 2.0 on Red Hat Enterprise Linux | rh-dotnet20-curl | Out of support scope | n/a |
| .NET Core 2.1 on Red Hat Enterprise Linux | rh-dotnet21-curl | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | curl | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | curl | Will not fix | n/a |
| Red Hat Enterprise Virtualization 3 | mingw-virt-viewer | Will not fix | n/a |
| Red Hat JBoss Enterprise Web Server 3 | curl | Affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
AV:N/AC:L/Au:N/C:N/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (11 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 15.36% (0.15362) | 96.68th | v5 (v2026.06.15) |
| Jun 15, 2026 | 14.60% (0.14596) | 96.20th | v5 (v2026.06.15) |
| Jun 4, 2025 | 1.37% (0.01369) | 79.27th | v4 (v2025.03.14) |
| Jun 1, 2025 | 2.46% (0.02459) | 84.50th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.94% (0.00941) | 74.66th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.50% (0.00497) | 77.05th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.50% (0.00497) | 75.56th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.50% (0.00497) | 72.58th | v3 (v2023.03.01) |
| Mar 6, 2023 | 3.78% (0.03779) | 85.48th | v2 (v2022.01.01) |
| Apr 1, 2022 | 3.78% (0.03779) | 84.01th | v2 (v2022.01.01) |
| Feb 4, 2022 | 3.78% (0.03779) | 67.21th | v2 (v2022.01.01) |
References (22)
- http://lists.opensuse.org/opensuse-updates/2016-09/msg00011.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-updates/2016-09/msg00094.html vendor-advisoryx_refsource_SUSEThird Party Advisory
- http://rhn.redhat.com/errata/RHSA-2016-2575.html vendor-advisoryx_refsource_REDHAT
- http://rhn.redhat.com/errata/RHSA-2016-2957.html vendor-advisoryx_refsource_REDHAT
- http://www.debian.org/security/2016/dsa-3638 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html x_refsource_CONFIRM
- http://www.securityfocus.com/bid/92309 vdb-entryx_refsource_BID
- http://www.securitytracker.com/id/1036537 vdb-entryx_refsource_SECTRACK
- http://www.securitytracker.com/id/1036739 vdb-entryx_refsource_SECTRACK
- http://www.slackware.com/security/viewer.php?l=slackware-security&y=2016&m=slackware-security.563059 vendor-advisoryx_refsource_SLACKWARE
- http://www.ubuntu.com/usn/USN-3048-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/errata/RHSA-2018:3558 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2016-5420 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1362190 Issue Tracking
- https://curl.haxx.se/docs/adv_20160803B.html x_refsource_MISCMitigationPatchVendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GLPXQQKURBQFM4XM6645VRPTOE2AWG33/ vendor-advisoryx_refsource_FEDORA
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K3GQH4V3XAQ5Z53AMQRDEC3C3UHTW7QR/ vendor-advisoryx_refsource_FEDORA
- https://nvd.nist.gov/vuln/detail/CVE-2016-5420
- https://security.gentoo.org/glsa/201701-47 vendor-advisoryx_refsource_GENTOO
- https://source.android.com/security/bulletin/2016-12-01.html x_refsource_CONFIRM
- https://www.cve.org/CVERecord?id=CVE-2016-5420
- https://www.tenable.com/security/tns-2016-18 x_refsource_CONFIRM
Change history (0)
No recorded changes yet.