Description
libcurl 7.1 through 7.57.0 might accidentally leak authentication data to third parties. When asked to send custom headers in its HTTP requests, libcurl will send that set of headers first to the host in the initial URL but also, if asked to follow redirects and a 30X HTTP response code is returned, to the host mentioned in URL in the `Location:` response header value. Sending the same set of headers to subsequent hosts is in particular a problem for applications that pass on custom `Authorization:` headers, as this header often contains privacy sensitive information or data that could allow others to impersonate the libcurl-using client's request.
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 | 7.58.0-1 | — |
| Debian 13 | curl | 7.58.0-1 | — |
| Debian 12 | curl | 7.58.0-1 | — |
| Debian 9 | curl | 7.52.1-5+deb9u4 | DSA-4098-1 |
| Debian 8 | curl | 7.38.0-4+deb8u9 | DSA-4098-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 7 | curl | 7.26.0-1+wheezy24 | DLA-1263-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | curl | 7.47.0-1ubuntu2.6 | USN-3554-1 |
| Ubuntu 14.04 LTS | curl | 7.35.0-1ubuntu2.14 | USN-3554-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | curl +2 | 7.29.0-51.el7 | RHSA-2018:3157 |
| RHEL 7 | nss-pem | 1.0.3-5.el7 | RHSA-2018:3157 |
| 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 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7.5 EUS | curl +2 | 7.29.0-46.el7_5.1 | RHSA-2020:0544 |
| RHEL 7.4 TUS | curl +2 | 7.29.0-42.el7_4.2 | RHSA-2020:0594 |
| RHEL 7.4 E4S | curl +2 | 7.29.0-42.el7_4.2 | RHSA-2020:0594 |
| RHEL 7.4 AUS | curl +2 | 7.29.0-42.el7_4.2 | RHSA-2020:0594 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | curl | 7.37.0-37.14.1 | SUSE-SU-2018:0217-1 |
| SLES 12 SP2 | curl | 7.37.0-37.14.1 | SUSE-SU-2018:0217-1 |
| SLES 11 SP4 | curl | 7.19.7-1.70.13.1 | SUSE-SU-2018:0230-1 |
| SLES 11 | curl-openssl1 | 7.19.7-1.70.13.1 | SUSE-SU-2018:0230-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Studio Onsite 1.3 | curl | 7.19.7-1.20.53.13.1 | SUSE-SU-2018:0214-1 |
| SLES for SAP 12 SP3 | curl | 7.37.0-37.14.1 | SUSE-SU-2018:0217-1 |
| SLES for SAP 12 SP2 | curl | 7.37.0-37.14.1 | SUSE-SU-2018:0217-1 |
| SLES for SAP 11 SP4 | curl | 7.19.7-1.70.13.1 | SUSE-SU-2018:0230-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | curl +2 | 7.55.1-9.amzn2.0.1 | ALAS2-2018-951 |
| Amazon Linux 2 | nss-pem | 1.0.3-5.amzn2 | ALAS2-2019-1139 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | curl +2 | 7.29.0-51.el7 | ELSA-2018-3157 |
| Oracle Linux 7 | nss-pem | 1.0.3-5.el7 | ELSA-2018-3157 |
Advisories 15
- RHSA-2020:0594 Red Hat Security Advisory: curl security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2020:0544 Red Hat Security Advisory: curl security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2018:3558 Red Hat Security Advisory: httpd24 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2018:3157 Red Hat Security Advisory: curl and nss-pem security and bug fix update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- USN-3554-1 curl vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4098-1 curl - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1263-1 curl - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2018:0217-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0230-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0214-1 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
- WID-SEC-2023-0890 libcurl: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jul 29, 2025
- ALAS2-2019-1139 Moderate: nss-pem security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jan 9, 2019
- ELSA-2018-3157 Moderate: curl and nss-pem security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 5, 2018
- ALAS2-2018-951 Important: curl security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 5, 2018
References
- USN-3554-2 vendor-advisory
- USN-3554-1 vendor-advisory
- RHSA-2018:3558 vendor-advisory
- DSA-4098 vendor-advisory
- https://curl.haxx.se/docs/adv_2018-b3bf.html
- 1040274 vdb-entry
- RHSA-2018:3157 vendor-advisory
- [debian-lts-announce] 20180129 [SECURITY] [DLA 1263-1] curl security update mailing-list
- RHBA-2019:0327 vendor-advisory
- RHSA-2019:1543 vendor-advisory
- https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
- RHSA-2020:0544 vendor-advisory
- RHSA-2020:0594 vendor-advisory
- [oss-security] 20220427 [SECURITY ADVISORY] curl auth/cookie leak on redirect mailing-list