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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | curl | 7.50.1-1 | — |
| Debian 13 | curl | 7.50.1-1 | — |
| Debian 12 | curl | 7.50.1-1 | — |
| Debian 8 | curl | 7.38.0-4+deb8u4 | DSA-3638-1 |
| Debian 7 | curl | 7.26.0-1+wheezy14 | DLA-586-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | curl | 7.47.0-1ubuntu2.1 | USN-3048-1 |
| Ubuntu 14.04 LTS | curl | 7.35.0-1ubuntu2.8 | USN-3048-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | curl +2 | 7.29.0-35.el7 | RHSA-2016:2575 |
| RHEL 3 | httpd24-curl +2 | 7.61.1-1.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-httpd +5 | 2.4.34-7.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-mod_md | 2.4.34-7.el7 | RHSA-2018:3558 |
| RHEL 3 | httpd24-mod_ssl +1 | 1:2.4.34-7.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-nghttp2 +2 | 1.7.1-7.el6 | RHSA-2018:3558 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | curl | 7.37.0-28.1 | SUSE-SU-2016:2330-1 |
| SLES 11 SP4 | curl | 7.19.7-1.61.1 | SUSE-SU-2016:2449-1 |
| SLES 11 SP3 | curl +1 | 7.19.7-1.61.1 | SUSE-SU-2016:2449-1 |
| SLES 11 | curl-openssl1 | 7.19.7-1.61.1 | SUSE-SU-2016:2449-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Studio Onsite 1.3 | curl | 7.19.7-1.20.42.1 | SUSE-SU-2016:2700-1, SUSE-SU-2016:2155-1 |
| SLES for SAP 12 SP1 | curl | 7.37.0-28.1 | SUSE-SU-2016:2330-1 |
| SLES for SAP 11 SP4 | curl | 7.19.7-1.61.1 | SUSE-SU-2016:2449-1 |
| SUSE OpenStack Cloud 5 | curl | 7.19.7-1.61.1 | SUSE-SU-2016:2449-1 |
| SUSE Manager Proxy 2.1 | curl | 7.19.7-1.61.1 | SUSE-SU-2016:2449-1 |
| SUSE Manager 2.1 | curl | 7.19.7-1.61.1 | SUSE-SU-2016:2449-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | curl | 7.19.7-1.61.1 | SUSE-SU-2016:2449-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | curl | 7.50.1-r0 | — |
| Alpine v3.23 | curl | 7.50.1-r0 | — |
| Alpine v3.22 | curl | 7.50.1-r0 | — |
| Alpine v3.21 | curl | 7.50.1-r0 | — |
| Alpine v3.20 | curl | 7.50.1-r0 | — |
Show 18 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | curl | 7.50.1-r0 | — |
| Alpine v3.18 | curl | 7.50.1-r0 | — |
| Alpine v3.17 | curl | 7.50.1-r0 | — |
| Alpine v3.16 | curl | 7.50.1-r0 | — |
| Alpine v3.15 | curl | 7.50.1-r0 | — |
| Alpine v3.14 | curl | 7.50.1-r0 | — |
| Alpine v3.13 | curl | 7.50.1-r0 | — |
| Alpine v3.12 | curl | 7.50.1-r0 | — |
| Alpine v3.11 | curl | 7.50.1 | — |
| Alpine v3.10 | curl | 7.50.1-r0 | — |
| Alpine v3.9 | curl | 7.50.1-r0 | — |
| Alpine v3.8 | curl | 7.50.1 | — |
| Alpine v3.7 | curl | 7.50.1 | — |
| Alpine v3.6 | curl | 7.50.1 | — |
| Alpine v3.5 | curl | 7.50.1-r0 | — |
| Alpine v3.4 | curl | 7.50.1-r0 | — |
| Alpine v3.3 | curl | 7.49.1-r1 | — |
| Alpine v3.2 | curl | 7.49.1-r1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | curl +2 | 7.29.0-35.el7 | ELSA-2016-2575 |
Advisories 11
- RHSA-2018:3558 Red Hat Security Advisory: httpd24 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2016:2575 Red Hat Security Advisory: curl security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- USN-3048-1 curl vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-586-1 curl - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3638-1 curl - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2016:2449-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2155-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2700-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2330-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2026-0180 Dell Data Protection Advisor: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 20, 2026
- ELSA-2016-2575 Moderate: curl security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 9, 2016
References
- RHSA-2016:2575 vendor-advisory
- RHSA-2018:3558 vendor-advisory
- 92309 vdb-entry
- https://source.android.com/security/bulletin/2016-12-01.html
- SSA:2016-219-01 vendor-advisory
- 1036739 vdb-entry
- DSA-3638 vendor-advisory
- openSUSE-SU-2016:2227 vendor-advisory
- https://www.tenable.com/security/tns-2016-18
- openSUSE-SU-2016:2379 vendor-advisory
- 1036537 vdb-entry
- FEDORA-2016-24316f1f56 vendor-advisory
- http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
- https://curl.haxx.se/docs/adv_20160803B.html
- FEDORA-2016-8354baae0f vendor-advisory
- RHSA-2016:2957 vendor-advisory
- GLSA-201701-47 vendor-advisory
- USN-3048-1 vendor-advisory