How severe is CVE-2026-11564?

CVE-2026-11564 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-11564 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-11564?

CVE-2026-11564 affects Haxx Curl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-11564?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-11564 published?

CVE-2026-11564 was published on 2026-07-03 and last updated on 2026-07-07.

CVE-2026-11564

CVE-2026-11564 is a critical-severity vulnerability in Haxx Curl with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Haxx Curl
Published: 2026-07-03
Last modified: 2026-07-07

Description

libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. An easy handle that first uses default native CA trust can continue trusting the native platform store after the application switches that same handle to custom CA material for a later transfer.

Frequently asked questions

What is CVE-2026-11564?: libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. An easy handle that first uses default native CA trust can continue trusting the native platform store after the application switches that same handle to custom CA material for a later transfer.
How severe is CVE-2026-11564?: CVE-2026-11564 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-11564 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-11564?: CVE-2026-11564 affects Haxx Curl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-11564?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-11564 published?: CVE-2026-11564 was published on 2026-07-03 and last updated on 2026-07-07.

References

Affected products (1)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

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