Mozilla Firefox up to 128.6/134.x Custom Highlight API use after free

CVSS Meta Temp Score
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CTI Interest Score
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8.2$5k-$25k1.99

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 128.6/134.x. It has been classified as critical. This affects an unknown function of the component Custom Highlight API. Performing a manipulation results in use after free. This vulnerability is identified as CVE-2025-1010. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 128.6/134.x. It has been classified as critical. This affects an unknown code block of the component Custom Highlight API. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

An attacker could have caused a use-after-free via the Custom Highlight API, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

The advisory is shared at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2025-1010 since 02/04/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 04/15/2026).

The vulnerability scanner Nessus provides a plugin with the ID 214965 (Mozilla Firefox < 135.0), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 128.7 or 135 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (214965). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.3
VulDB Meta Temp Score: 8.2

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

ADP CISA Base Score: 9.8
ADP CISA Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
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: 214965
Nessus Name: Mozilla Firefox < 135.0

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Firefox 128.7/135

Timelineinfo

02/04/2025 🔍
02/04/2025 +0 days 🔍
02/04/2025 +0 days 🔍
04/15/2026 +435 days 🔍

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2025-1010 (🔍)
GCVE (CVE): GCVE-0-2025-1010
GCVE (VulDB): GCVE-100-294621

Entryinfo

Created: 02/04/2025 15:44
Updated: 04/15/2026 07:31
Changes: 02/04/2025 15:44 (56), 02/04/2025 22:11 (2), 02/05/2025 22:59 (3), 04/15/2026 07:31 (22)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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