Read the docs
TI-2016-04696 Aliases CVE-2016-5420GHSA-qpjh-642g-hgh8

curl and libcurl before 7.50.1 do not check the client certificate when choosing the TLS…

Priority MEDIUM 49CWE-285Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
Partial Red Hat: 14 fixed, 8 without a fix

Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-285.

Summary

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.

Why it matters now

EPSS 0.15362 96th percentileScored 2026-11-07
Fix Partial Red Hat: 3 advisoriesRed Hat: 14 fixed, 8 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*8.0VulnerableDebian
cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:*up to 7.50.0VulnerableHaxx
cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*42.1VulnerableopenSUSE
  • cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
  • cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:* Versions up to 7.50.0 Vulnerable ·Haxx
  • cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:* Versions 42.1 Vulnerable ·openSUSE

Remediation

Red Hat 3 advisories

  • RHSA-2018:3558 Released 2018-11-13 · Red Hat rating Moderate
    httpd24 security, bug fix, and enhancement update
    • Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 6) httpd24-curl-7.61.1-1.el6, httpd24-httpd-2.4.34-7.el6, httpd24-httpd-devel-2.4.34-7.el6 +11
    • Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7) httpd24-curl-7.61.1-1.el7, httpd24-httpd-2.4.34-7.el7, httpd24-httpd-devel-2.4.34-7.el7 +12
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.4) httpd24-curl-7.61.1-1.el7, httpd24-httpd-2.4.34-7.el7, httpd24-httpd-devel-2.4.34-7.el7 +12
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.5) httpd24-curl-7.61.1-1.el7, httpd24-httpd-2.4.34-7.el7, httpd24-httpd-devel-2.4.34-7.el7 +12
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.6) httpd24-curl-7.61.1-1.el7, httpd24-httpd-2.4.34-7.el7, httpd24-httpd-devel-2.4.34-7.el7 +12
    • Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 6) httpd24-curl-7.61.1-1.el6, httpd24-httpd-2.4.34-7.el6, httpd24-httpd-devel-2.4.34-7.el6 +11
    • Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7) httpd24-curl-7.61.1-1.el7, httpd24-httpd-2.4.34-7.el7, httpd24-httpd-devel-2.4.34-7.el7 +12
  • RHSA-2016:2957 Released 2016-12-15 · Red Hat rating Important
    Red Hat JBoss Core Services Apache HTTP 2.4.23 Release
    • Red Hat JBoss Core Services
  • RHSA-2016:2575 Released 2016-11-03 · Red Hat rating Moderate
    curl security, bug fix, and enhancement update
    • Red Hat Enterprise Linux Client (v. 7) curl-7.29.0-35.el7, libcurl-7.29.0-35.el7
    • Red Hat Enterprise Linux Client Optional (v. 7) libcurl-devel-7.29.0-35.el7
    • Red Hat Enterprise Linux ComputeNode (v. 7) curl-7.29.0-35.el7, libcurl-7.29.0-35.el7
    • Red Hat Enterprise Linux ComputeNode Optional (v. 7) libcurl-devel-7.29.0-35.el7
    • Red Hat Enterprise Linux Server (v. 7) curl-7.29.0-35.el7, libcurl-7.29.0-35.el7, libcurl-7.29.0-35.el7.ppc +2
    • Red Hat Enterprise Linux Workstation (v. 7) curl-7.29.0-35.el7, libcurl-7.29.0-35.el7, libcurl-devel-7.29.0-35.el7

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
.NET Core 1.0 on Red Hat Enterprise LinuxAffectedNo fix planned: Out of support scope
.NET Core 1.1 on Red Hat Enterprise LinuxAffectedNo fix planned: Out of support scope
.NET Core 2.0 on Red Hat Enterprise LinuxAffectedNo fix planned: Out of support scope
.NET Core 2.1 on Red Hat Enterprise LinuxAffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 5AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Will not fix
Red Hat Enterprise Virtualization 3AffectedNo fix planned: Will not fix
Red Hat JBoss Enterprise Web Server 3AffectedNo fix yet
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2016:2575
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2016:2575
Red Hat Enterprise Linux ComputeNode (v. 7)Fixed RHSA-2016:2575
Red Hat Enterprise Linux ComputeNode Optional (v. 7)Fixed RHSA-2016:2575
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2016:2575
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2016:2575
Red Hat JBoss Core ServicesFixed RHSA-2016:2957
Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 6)Fixed RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.4)Fixed RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.5)Fixed RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.6)Fixed RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 6)Fixed RHSA-2018:3558
Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2018:3558

Timeline

  1. 2026-10-02 Threatist record created from CVE-2016-5420
  2. 2026-10-03 Alias added: GHSA-qpjh-642g-hgh8

References

Patch 1

Advisory 11

Other 3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences