Mozilla Firefox up to 153.3/156 Networking HTTP data authenticity

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.0$5k-$25k0.35-

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 153.3/156. It has been classified as critical. The affected element is an unknown function of the component Networking HTTP. The manipulation leads to data authenticity. This vulnerability is referenced as CVE-2026-100822. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 153.3/156 and classified as critical. This issue affects an unknown code block of the component Networking HTTP. The manipulation with an unknown input leads to a data authenticity vulnerability. Using CWE to declare the problem leads to CWE-345. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Spoofing issue in the Networking: HTTP component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.

It is possible to read the advisory at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2026-100822 since 09/26/2026. 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 09/29/2026).

Upgrading to version 153.4 or 157 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality 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: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
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: Data authenticity
CWE: CWE-345
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 153.4/157

Timelineinfo

09/26/2026 CVE reserved
09/29/2026 +3 days Advisory disclosed
09/29/2026 +0 days VulDB entry created
09/29/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-100822 (🔒)
GCVE (CVE): GCVE-0-2026-100822
GCVE (VulDB): GCVE-100-411395

Entryinfo

Created: 09/29/2026 15:44
Changes: 09/29/2026 15:44 (57)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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