How severe is CVE-2026-3784?

CVE-2026-3784 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-3784 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3784?

CVE-2026-3784 affects Haxx Curl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-3784?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-3784 have an EU (EUVD) identifier?

Yes. CVE-2026-3784 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11139.

When was CVE-2026-3784 published?

CVE-2026-3784 was published on 2026-03-11 and last updated on 2026-06-17.

CVE-2026-3784

CVE-2026-3784 is a medium-severity vulnerability in Haxx Curl with a CVSS 3.x base score of 6.5. 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-305.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-11139
Weakness: CWE-305
Affected product: Haxx Curl
Published: 2026-03-11
Last modified: 2026-06-17

Description

curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection.

Frequently asked questions

What is CVE-2026-3784?: curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection.
How severe is CVE-2026-3784?: CVE-2026-3784 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-3784 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3784?: CVE-2026-3784 affects Haxx Curl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-3784?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3784 have an EU (EUVD) identifier?: Yes. CVE-2026-3784 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11139.
When was CVE-2026-3784 published?: CVE-2026-3784 was published on 2026-03-11 and last updated on 2026-06-17.

References

Affected products (1)

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

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