CVE-2026-8458
MEDIUMDescription
libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different 'services'. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.
Is your site exposed to CVE-2026-8458?
Run a free security scan — no signup, results in seconds.
CVSS v3.1 Score
EPSS — Exploit Prediction
EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.
Affected Products
| Vendor | Product |
|---|---|
| haxx | curl |
References
Frequently Asked Questions
What is CVE-2026-8458? +
How severe is CVE-2026-8458? +
What products are affected by CVE-2026-8458? +
How do I check if I'm vulnerable to CVE-2026-8458? +
Related Vulnerabilities
Successfully using libcurl to do a transfer to a specific HTTP origin (`hostA`) with **Digest** authentication and then changing the …
libcurl had a flaw that when instructed to clear proxy authentication credentials which made it not do so, leaving the …
A use-after-free vulnerability exists in libcurl when an application configures an HTTP/2 stream-dependency tree via `CURLOPT_STREAM_DEPENDS` or `CURLOPT_STREAM_DEPENDS_E`, subsequently invokes …
The curl logic that works with SASL authentication could end up cleaning up the GSASL context *twice* without clearing the …
A flaw in curl’s cookie parsing logic allows a malicious HTTP server to set 'super cookies' that bypass the Public …
When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication …