CVE-2026-80231: curl — Exploit & Fix

Description

A flaw in libcurl makes it wrongly reuse an existing HTTPS connection setup for a given hostname even when using a different Native CA Store setting (`CURLSSLOPT_NATIVE_CA`) than when the connection was created.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0090

Probability of exploitation

0.58%

Percentile rank

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.

Weakness Type (CWE)

CWE-488 CWE-488

Affected Products

Vendor	Product	Versions
haxx	curl	7.71.0 — 8.22.0

References

Advisories & Patches

https://curl.se/docs/CVE-2026-80231.html https://curl.se/docs/CVE-2026-80231.json

Exploits

https://hackerone.com/reports/3969368 https://hackerone.com/reports/3969368

Frequently Asked Questions

What is CVE-2026-80231? +

A flaw in libcurl makes it wrongly reuse an existing HTTPS connection setup for a given hostname even when using a different Native CA Store setting (`CURLSSLOPT_NATIVE_CA`) than when the connection was created. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-80231? +

CVE-2026-80231 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0090, placing it in the 1th percentile for exploitation probability.

What products are affected by CVE-2026-80231? +

CVE-2026-80231 affects products from haxx, specifically: curl. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-80231? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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