CVE intelligence

CVE-2025-1861

Vulnerability intelligence

Published Mar 30, 2025Sources checked Sep 30, 2026

9.8CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2025-1861 and is rated Critical severity with a CVSS score of 9.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

CBL-Mariner Releases

Vendor-listed releases

8.3.19-1
8.1.32-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.8%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2025-1861?

In PHP from 8.1.* before 8.1.32, from 8.2.* before 8.2.28, from 8.3.* before 8.3.19, from 8.4.* before 8.4.5, when parsing HTTP redirect in the response to an HTTP request, there is currently limit on the location value size caused by limited size of the location buffer to 1024. However as per RFC9110, the limit is recommended to be 8000. This may lead to incorrect URL truncation and redirecting to a wrong location.