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Vulnerability record · CVE-2026-11352 · published 3 July 2026

CVE-2026-11352: Haxx curl vulnerability

Haxx · Curl

An issue in curl’s QUIC UDP receive function allows a malicious HTTP/3 server to trigger a remote denial of service against a curl or libcurl client. Because the helper function discards zero-length UDP datagrams before counting them toward the per-call packet budget, a connected QUIC peer can continuously stream empty datagrams to indefinitely stall the client.

7.5 CVSS 3.1 High EPSS 0.72% · top 48.2% CWE-835 · CWE-835
7.5CVSS 3.1 base score
0.72%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References, 2 tagged exploit
15 Sep 2026Last modified by NVD

Description

An issue in curl’s QUIC UDP receive function allows a malicious HTTP/3 server to trigger a remote denial of service against a curl or libcurl client. Because the helper function discards zero-length UDP datagrams before counting them toward the per-call packet budget, a connected QUIC peer can continuously stream empty datagrams to indefinitely stall the client.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://curl.se/docs/CVE-2026-11352.html PatchVendor Advisory
https://curl.se/docs/CVE-2026-11352.json Vendor Advisory
https://hackerone.com/reports/3783438 ExploitIssue TrackingThird Party Advisory
https://hackerone.com/reports/3783438 ExploitIssue TrackingThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-11352), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.