CVE-2016-9594 Weak cryptography in curl

What is CVE-2016-9594?

CVE-2016-9594 is a medium-severity vulnerability in Haxx Curl, published on 23 Apr 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

curl before version 7.52.1 is vulnerable to an uninitialized random in libcurl's internal function that returns a good 32bit random value. Having a weak or virtually non-existent random value makes the operations that use it vulnerable.

Weakness: CWE-665

Which versions are affected by CVE-2016-9594?

It affects 1 product.

Products include Haxx Curl.

How do I fix CVE-2016-9594?

Upgrade to a fixed version.

Is CVE-2016-9594 being exploited?

There is no known exploitation of CVE-2016-9594 in the wild and no public exploit code.

Other vulnerabilities in Haxx Curl

• CVE-2026-19931 Negotiate ambient user conn reuse Critical 9.8
• CVE-2026-10536 HTTP/2 stream-dependency tree UAF Critical 9.8
• CVE-2026-11856 cross-origin Digest auth state leak Critical 9.8
• CVE-2026-8925 SASL double-free Critical 9.8
• CVE-2026-9079 stale proxy password leak Critical 9.8

All Haxx Curl vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2016-9594, CLEANSTART-2026-QX18395, CURL-CVE-2016-9594, GHSA-qq6c-xrmh-q72x.