CVE-2025-3839Network attack vectorHinoki check available

Conditional code execution via ungated external URI handlers

Published Jan 23, 2026 · Updated Jan 23, 2026

Improper UI gating in GNOME Web before 47.5 and 48.0 allows remote attackers to invoke external URI handlers from web content. The navigation policy hands non-web URI schemes to desktop applications without first requiring a user gesture or explicit confirmation. A user must load attacker-controlled content, and code execution depends on a registered external handler containing an independently exploitable flaw.

CVSS severity8.0
High
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper UI gating in GNOME Web before 47.5 and 48.0 allows remote attackers to invoke external URI handlers from web content. The navigation policy hands non-web URI schemes to desktop applications without first requiring a user gesture or explicit confirmation. A user must load attacker-controlled content, and code execution depends on a registered external handler containing an independently exploitable flaw.

The record

CVE
CVE-2025-3839
Published
Jan 23, 2026
Updated
Jan 23, 2026
Vendor
XMLSoft
Product
GNOME Web
Classifications
CWE-356, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <47.5
  2. Affected versionversion=48.0 <48.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

XMLSoft · GNOME Webversion=0 <47.5; version=48.0 <48.1

Published CVSS scores

8.0Fedora ProjectCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-356Product UI does not Warn User of Unsafe Actions
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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