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Vulnerability record · CVE-2026-11586 · published 3 July 2026

CVE-2026-11586: Haxx curl allocation without limits vulnerability

Haxx · Curl

By default, curl automatically responds to WebSocket PING frames. Because curl lacks an upper bound on memory allocation for unacknowledged frames, a malicious server can exhaust all available memory by flooding curl with rapid, sequential PING messages.

7.5 CVSS 3.1 High EPSS 0.61% · top 53.0% CWE-770 · Allocation without limits
7.5CVSS 3.1 base score
0.61%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References, 1 tagged exploit
15 Sep 2026Last modified by NVD

Description

By default, curl automatically responds to WebSocket PING frames. Because curl lacks an upper bound on memory allocation for unacknowledged frames, a malicious server can exhaust all available memory by flooding curl with rapid, sequential PING messages.

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-2026-11586.html PatchVendor Advisory
https://curl.se/docs/CVE-2026-11586.json Vendor Advisory
https://hackerone.com/reports/3788931 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-2026-11586), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.