CVE-2026-11352

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 v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://curl.se/docs/CVE-2026-11352.html	Patch Vendor Advisory
https://curl.se/docs/CVE-2026-11352.json	Vendor Advisory
https://hackerone.com/reports/3783438	Exploit Issue Tracking Third Party Advisory
https://hackerone.com/reports/3783438	Exploit Issue Tracking Third Party Advisory

Configurations

Configuration 1 (hide)

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

History

No history.

Information

Published : 2026-07-03 07:16

Updated : 2026-09-15 07:16

NVD link : CVE-2026-11352

Mitre link : CVE-2026-11352

CVE.ORG link : CVE-2026-11352

JSON object : View

Products Affected

haxx

curl

CWE

CWE-835

Loop with Unreachable Exit Condition ('Infinite Loop')

{"id": "CVE-2026-11352", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-11352", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-06T18:26:03.249042Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "2499f714-1537-4658-8207-48ae4bb9eae9", "affectedData": [{"vendor": "curl", "product": "curl", "versions": [{"status": "affected", "version": "8.18.0", "lessThan": "8.20.1", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"repo": "https://github.com/curl/curl.git", "vendor": "curl", "product": "curl", "versions": [{"status": "affected", "version": "6a3d0b6d631d5e9bec797306b5b41a9f440a088d", "lessThan": "56eca2afb4806f1032872fa97d1834b3c1385276", "versionType": "git"}], "defaultStatus": "unaffected"}, {"vendor": "curl", "product": "curl", "versions": [{"status": "affected", "version": "8.20.0"}, {"status": "affected", "version": "8.19.0"}, {"status": "affected", "version": "8.18.0"}], "defaultStatus": "unaffected"}]}], "published": "2026-07-03T07:16:23.693", "references": [{"url": "https://curl.se/docs/CVE-2026-11352.html", "tags": ["Patch", "Vendor Advisory"], "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://curl.se/docs/CVE-2026-11352.json", "tags": ["Vendor Advisory"], "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://hackerone.com/reports/3783438", "tags": ["Exploit", "Issue Tracking", "Third Party Advisory"], "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://hackerone.com/reports/3783438", "tags": ["Exploit", "Issue Tracking", "Third Party Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Secondary", "source": "2499f714-1537-4658-8207-48ae4bb9eae9", "description": [{"lang": "en", "value": "CWE-835"}]}, {"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-835"}]}], "descriptions": [{"lang": "en", "value": "An issue in curl\u2019s QUIC UDP receive function allows a malicious HTTP/3 server\nto trigger a remote denial of service against a curl or libcurl client.\nBecause the helper function discards zero-length UDP datagrams before counting\nthem toward the per-call packet budget, a connected QUIC peer can continuously\nstream empty datagrams to indefinitely stall the client."}], "lastModified": "2026-09-15T07:16:25.353", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6EF934FA-9E74-432D-A41E-157D65C6B539", "versionEndExcluding": "8.21.0", "versionStartIncluding": "8.18.0"}], "operator": "OR"}]}], "sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9"}