CVE-2025-66286 | Webkitgtk: authorization bypass through webpage::send-request signal handler

An API design flaw in WebKitGTK and WPE WebKit allows untrusted web content to unexpectedly perform IP connections, DNS lookups, and HTTP requests. Applications expect to use the WebPage::send-request signal handler to approve or reject all network requests. However, certain types of HTTP requests bypass this signal handler.

Published: 2026-04-23 Last update: 2026-04-24 Assigner: [email protected] Source: [email protected]
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-66286 is rated Low Risk (21.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-66286

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-24 — 0.03% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-66286

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.7 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]

Weakness enumeration for CVE-2025-66286

GitHub Security Advisory for CVE-2025-66286

GHSA-qx86-g93j-m25r · Severity: medium — An API design flaw in WebKitGTK and WPE WebKit allows untrusted web content to unexpectedly...

OS Trackers for CVE-2025-66286

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2025-66286
suse medium — https://www.suse.com/security/cve/CVE-2025-66286/
ubuntu medium CVE-2025-66286 medium priority: Ubuntu including 5 source packages (qtwebkit-opensource-src, qtwebkit-source, webkit2gtk, webkitgtk, wpewebkit), 36 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): ignored 15, DNE 13, needs-triage 5, deferred 3. https://ubuntu.com/security/CVE-2025-66286

Affected software / configurations for CVE-2025-66286

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-66286

cvelogic Threat Intelligence