Mozilla Firefox up to 158 CSS Parsing/Computation cross site scripting

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.1$0-$5k0.64+

Summaryinfo

A vulnerability, which was classified as problematic, was found in Mozilla Firefox up to 158. This affects an unknown function of the component CSS Parsing/Computation. The manipulation results in cross site scripting. This vulnerability is known as CVE-2026-118011. It is possible to launch the attack remotely. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 158. It has been classified as problematic. Affected is some unknown functionality of the component CSS Parsing/Computation. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

Frame poisoning in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 159.

The advisory is shared for download at bugzilla.mozilla.org. This vulnerability is traded as CVE-2026-118011 since 10/27/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/27/2026). The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 159 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

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: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 159

Timelineinfo

10/27/2026 Advisory disclosed
10/27/2026 +0 days CVE reserved
10/27/2026 +0 days VulDB entry created
10/27/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-118011 (🔒)
GCVE (CVE): GCVE-0-2026-118011
GCVE (VulDB): GCVE-100-427380

Entryinfo

Created: 10/27/2026 16:07
Changes: 10/27/2026 16:07 (57)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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