CVE-2025-47908

Denial of service via malicious preflight requests in github.com/rs/cors

Published Aug 6, 2025 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Middleware causes a prohibitive amount of heap allocations when processing malicious preflight requests that include a Access-Control-Request-Headers (ACRH) header whose value contains many commas. This behavior can be abused by attackers to produce undue load on the middleware/server as an attempt to cause a denial of service.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-23882 Middleware causes a prohibitive amount of heap allocations when processing malicious preflight requests that include a Access-Control-Request-Headers (ACRH) header whose value contains many commas. This behavior can be abused by attackers to produce undue load on the middleware/server as an attempt to cause a denial of service.
Github GHSA Github GHSA GHSA-mh55-gqvf-xfwm Denial of service via malicious preflight requests in github.com/rs/cors
History
Type Values Removed Values Added
First Time appeared Golang
Golang cors
Vendors & Products Golang
Golang cors
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
Weaknesses CWE-770
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Moderate

Type Values Removed Values Added
Description Middleware causes a prohibitive amount of heap allocations when processing malicious preflight requests that include a Access-Control-Request-Headers (ACRH) header whose value contains many commas. This behavior can be abused by attackers to produce undue load on the middleware/server as an attempt to cause a denial of service.
Title Denial of service via malicious preflight requests in github.com/rs/cors
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Go
Published
Updated
Aug 7, 2025, 1:47 PM
Reserved
May 13, 2025, 11:31 PM
Status
Deferred
Published
Aug 6, 2025, 9:15 PM
Modified
Jun 17, 2026, 9:28 AM
Severity
Moderate
Public date
Aug 6, 2025, 8:41 PM