Home / mailings [USN-8651-1] curl vulnerability
Posted on 19 August 2026
Ubuntu Security==========================================================================Ubuntu Security Notice USN-8651-1
August 19, 2026
curl vulnerability
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 26.04 LTS
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS
Summary:
curl could be made to expose sensitive information over the network.
Software Description:
- curl: HTTP, HTTPS, and FTP client and client libraries
Details:
It was discovered that curl incorrectly handled reusing connections
when the origin changed between transfers. A remote attacker could
possibly use this issue to obtain sensitive information.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 26.04 LTS
curl 8.18.0-1ubuntu2.4
libcurl3t64-gnutls 8.18.0-1ubuntu2.4
libcurl4-gnutls-dev 8.18.0-1ubuntu2.4
libcurl4-openssl-dev 8.18.0-1ubuntu2.4
libcurl4t64 8.18.0-1ubuntu2.4
Ubuntu 24.04 LTS
curl 8.5.0-2ubuntu10.12
libcurl3t64-gnutls 8.5.0-2ubuntu10.12
libcurl4-gnutls-dev 8.5.0-2ubuntu10.12
libcurl4-openssl-dev 8.5.0-2ubuntu10.12
libcurl4t64 8.5.0-2ubuntu10.12
Ubuntu 22.04 LTS
curl 7.81.0-1ubuntu1.26
libcurl3-gnutls 7.81.0-1ubuntu1.26
libcurl3-nss 7.81.0-1ubuntu1.26
libcurl4 7.81.0-1ubuntu1.26
libcurl4-gnutls-dev 7.81.0-1ubuntu1.26
libcurl4-nss-dev 7.81.0-1ubuntu1.26
libcurl4-openssl-dev 7.81.0-1ubuntu1.26
Ubuntu 20.04 LTS
curl 7.68.0-1ubuntu2.25+esm6
Available with Ubuntu Pro
libcurl3-gnutls 7.68.0-1ubuntu2.25+esm6
Available with Ubuntu Pro
libcurl3-nss 7.68.0-1ubuntu2.25+esm6
Available with Ubuntu Pro
libcurl4 7.68.0-1ubuntu2.25+esm6
Available with Ubuntu Pro
libcurl4-gnutls-dev 7.68.0-1ubuntu2.25+esm6
Available with Ubuntu Pro
libcurl4-nss-dev 7.68.0-1ubuntu2.25+esm6
Available with Ubuntu Pro
libcurl4-openssl-dev 7.68.0-1ubuntu2.25+esm6
Available with Ubuntu Pro
Ubuntu 18.04 LTS
curl 7.58.0-2ubuntu3.24+esm11
Available with Ubuntu Pro
libcurl3-gnutls 7.58.0-2ubuntu3.24+esm11
Available with Ubuntu Pro
libcurl3-nss 7.58.0-2ubuntu3.24+esm11
Available with Ubuntu Pro
libcurl4 7.58.0-2ubuntu3.24+esm11
Available with Ubuntu Pro
libcurl4-gnutls-dev 7.58.0-2ubuntu3.24+esm11
Available with Ubuntu Pro
libcurl4-nss-dev 7.58.0-2ubuntu3.24+esm11
Available with Ubuntu Pro
libcurl4-openssl-dev 7.58.0-2ubuntu3.24+esm11
Available with Ubuntu Pro
Ubuntu 16.04 LTS
curl 7.47.0-1ubuntu2.19+esm18
Available with Ubuntu Pro
libcurl3 7.47.0-1ubuntu2.19+esm18
Available with Ubuntu Pro
libcurl3-gnutls 7.47.0-1ubuntu2.19+esm18
Available with Ubuntu Pro
libcurl3-nss 7.47.0-1ubuntu2.19+esm18
Available with Ubuntu Pro
libcurl4-gnutls-dev 7.47.0-1ubuntu2.19+esm18
Available with Ubuntu Pro
libcurl4-nss-dev 7.47.0-1ubuntu2.19+esm18
Available with Ubuntu Pro
libcurl4-openssl-dev 7.47.0-1ubuntu2.19+esm18
Available with Ubuntu Pro
Ubuntu 14.04 LTS
curl 7.35.0-1ubuntu2.20+esm22
Available with Ubuntu Pro
libcurl3 7.35.0-1ubuntu2.20+esm22
Available with Ubuntu Pro
libcurl3-gnutls 7.35.0-1ubuntu2.20+esm22
Available with Ubuntu Pro
libcurl3-nss 7.35.0-1ubuntu2.20+esm22
Available with Ubuntu Pro
libcurl4-gnutls-dev 7.35.0-1ubuntu2.20+esm22
Available with Ubuntu Pro
libcurl4-nss-dev 7.35.0-1ubuntu2.20+esm22
Available with Ubuntu Pro
libcurl4-openssl-dev 7.35.0-1ubuntu2.20+esm22
Available with Ubuntu Pro
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8651-1
CVE-2026-11856
Package Information:
https://launchpad.net/ubuntu/+source/curl/8.18.0-1ubuntu2.4
https://launchpad.net/ubuntu/+source/curl/8.5.0-2ubuntu10.12
https://launchpad.net/ubuntu/+source/curl/7.81.0-1ubuntu1.26
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