VulnerabilityPublished 6 Aug 2026

CVE-2026-18487: GNOME Epiphany · User Interface (UI) Misrepresentation of Critical Information

Affects GNOME EpiphanySource CVE Database V5

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Not known to be exploited · CVSS 5.4 Medium.

Data as of 5 Nov 2026, 00:01 UTC

CVSS 3.1 base score

5.4Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GNOMEEpiphany	Affected >=49.2	Fixed in–
GitHubgnome/epiphany`pkg:github/gnome/epiphany`Other threats	Affected =49.2	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Red Hat states that this vulnerability does not affect any currently supported Red Hat products, so no action is required for those users. For other users of GNOME Epiphany, check the vendor's advisory or official sources for patches or updates addressing this issue.

Description

CVE-2026-18487 is a medium severity vulnerability in the GNOME Epiphany browser where the address bar can be spoofed. An attacker can craft a URL containing a colon and userinfo to make the address bar display a trusted domain while actually loading a malicious site. This UI misrepresentation can facilitate phishing attacks by misleading users about the true website they are visiting. Red Hat has assessed that this vulnerability does not affect any currently supported Red Hat products.

Impact

The vulnerability allows attackers to mislead users by displaying a trusted domain in the address bar while loading content from a malicious domain. This can enable phishing attacks by exploiting user trust in the displayed URL. The confidentiality and integrity of user interactions may be compromised due to this UI spoofing. There is no indication of impact on availability. No known exploits in the wild have been reported.

Summary

The vulnerability in GNOME Epiphany involves improper parsing of web addresses containing a colon in the userinfo section (e.g., https://trusted.com:80@attacker.com/). This causes the browser's address bar and security indicators to display the trusted domain (trusted.com) while the content is loaded from the attacker-controlled domain (attacker.com). This discrepancy allows attackers to create convincing phishing pages by misrepresenting the actual domain to users. The issue is classified as a User Interface (UI) Misrepresentation of Critical Information and is tracked as CVE-2026-18487 with a CVSS 3.1 score of 5.4 (medium severity). Red Hat's analysis confirms no impact on their supported products.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Aug 2026, 16:11 UTC

Technical details

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