Mozilla Firefox up to 146 PDF Viewer ui layer

CVSS Meta Temp Score
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CTI Interest Score
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4.1$5k-$25k0.00

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 146. It has been classified as problematic. Affected by this issue is some unknown functionality of the component PDF Viewer. The manipulation leads to ui layer. This vulnerability is listed as CVE-2026-0887. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 146 and classified as problematic. This issue affects an unknown code block of the component PDF Viewer. The manipulation with an unknown input leads to a ui layer vulnerability. Using CWE to declare the problem leads to CWE-1021. The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain, which can lead to user confusion about which interface the user is interacting with. Impacted is integrity. The summary by CVE is:

Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability affects Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.

It is possible to read the advisory at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2026-0887 since 01/13/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/11/2026).

The vulnerability scanner Nessus provides a plugin with the ID 284821 (RHEL 8 : firefox (RHSA-2026:0667)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 147 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (284821), EUVD (EUVD-2026-2078) and CERT Bund (WID-SEC-2026-0090). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Mozilla Firefox
  • Mozilla Firefox ESR
  • Mozilla Thunderbird

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Ui layer
CWE: CWE-1021
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 284821
Nessus Name: RHEL 8 : firefox (RHSA-2026:0667)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 147

Timelineinfo

01/13/2026 Advisory disclosed
01/13/2026 +0 days CVE reserved
01/13/2026 +0 days VulDB entry created
06/11/2026 +149 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-0887 (🔒)
GCVE (CVE): GCVE-0-2026-0887
GCVE (VulDB): GCVE-100-340583
EUVD: 🔒
CERT Bund: WID-SEC-2026-0090 - Mozilla Firefox und Thunderbird: Mehrere Schwachstellen

Entryinfo

Created: 01/13/2026 15:20
Updated: 06/11/2026 19:54
Changes: 01/13/2026 15:20 (56), 01/14/2026 02:11 (1), 01/15/2026 18:40 (1), 01/15/2026 19:35 (2), 01/15/2026 21:47 (7), 01/23/2026 01:41 (1), 06/11/2026 19:54 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

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