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.

Is your site exposed to CVE-2026-80231?

Run a free security scan — no signup, results in seconds.

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

0.0094

Probability of exploitation

0.59%

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 0.0094, 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.

Related Vulnerabilities

CVE-2024-8314

An Incorrect Implementation of Authentication Algorithm and Exposure of Data Element to Wrong Ses-sion vulnerability in the session handling used …

CVE-2026-82367

Exposure of Data Element to Wrong Session vulnerability in ash-project ash_graphql can deliver one subscription's resolved records to a different …

CVE-2026-16326 10.0

In consul-mcp-server, versions 0.1.0 up to 0.1.3 did not properly isolate session state in stateless mode, which may allow one …

CVE-2026-16498 10.0

The terraform-mcp-server before version 1.1.0 is vulnerable to a cross-tenant credential reuse issue in the streamable-HTTP stateless transport mode that …

CVE-2026-19931 9.8

A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given hostname using Negotiate authentication, when …

CVE-2025-47928 9.1

Spotipy is a Python library for the Spotify Web API. As of commit 4f5759dbfb4506c7b6280572a4db1aabc1ac778d, using `pull_request_target` on `.github/workflows/integration_tests.yml` followed by …

CVE-2026-80231