Is CVE-2026-2766 actively exploited?

No active exploitation of CVE-2026-2766 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-2766 be exploited remotely?

Yes. CVE-2026-2766 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-2766?

CVE-2026-2766 has a CVSS score of 9.8 (CRITICAL) and an EPSS exploitation probability of 0.04%.

HOME VULNERABILITIESCVE-2026-2766

CRITICAL

CVE-2026-2766

Published: February 24, 2026· Updated: Feb 28, 2026

9.8

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:13.8th

Official Description

Use-after-free in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

NVD Source

Technical Analysis

CVE-2026-2766 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected Vendors & Products

Mozilla2 products

firefoxthunderbird

Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Exploit-DB

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

PacketStorm

Security advisories & exploits

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://www.mozilla.org/security/advisories/mfsa2026-13/

ADVISORYhttps://www.mozilla.org/security/advisories/mfsa2026-15/

ADVISORYhttps://www.mozilla.org/security/advisories/mfsa2026-16/

ADVISORYhttps://www.mozilla.org/security/advisories/mfsa2026-17/

News & Research Mentioning CVE-2026-2766

Siemens RUGGEDCOM CROSSBOW Secure Access Manager Primary

CISA Alerts· Apr 21, 2026

View CSAF Summary RUGGEDCOM CROSSBOW Secure Access Manager Primary (SAM-P) contains a vulnerability that could allow an attacker to escalate their own privileges. Siemens has released a new version for RUGGEDCOM CROSSBOW Secure Access Manager Primary (SAM-P) and recommends to update to the latest version. The following versions of Siemens RUGGEDCOM CROSSBOW Secure Access Manager Primary are affected: RUGGEDCOM CROSSBOW Secure Access Manager Primary (SAM-P) vers:intdot/<5.8 (CVE-2026-27668) CVSS Vendor Equipment Vulnerabilities v3 8.8 Siemens Siemens RUGGEDCOM CROSSBOW Secure Access Manager Primary Incorrect Privilege Assignment Background Critical Infrastructure Sectors: Critical Manufacturing Countries/Areas Deployed: Worldwide Company Headquarters [xlite_meta score:63 src:CISA Alerts xlite_fp:07b695ce301725e724f4e5361692a085a20c29c7384e7cb5ccd2b1202c802740]

Siemens SICAM 8 Products

CISA Alerts· Apr 2, 2026

View CSAF Summary Multiple SICAM 8 products are affected by multiple vulnerabilities that could lead to denial of service, namely: - SICAM A8000 Device firmware - CPCI85 for CP-8031/CP-8050 - SICORE for CP-8010/CP-8012 - RTUM85 for CP-8010/CP-8012 - SICAM EGS Device firmware - CPCI85 - SICAM S8000 - SICORE - RTUM85 Siemens has released new versions for the affected products and recommends to update to the latest versions. The following versions of Siemens SICAM 8 Products are affected: CPCI85 Central Processing/Communication vers:intdot/<26.10 (CVE-2026-27663, CVE-2026-27664) RTUM85 RTU Base vers:intdot/<26.10 (CVE-2026-27663) SICORE Base system vers:intdot/<26.10.0 (CVE-2026-27664) CVSS Vendor Equipment Vulnerabilities v3 7.5 Siemens Siemens SICAM 8 [xlite_meta score:73 src:CISA Alerts xlite_fp:7d25bfddb354b705fe5c9e2f90b0fda6044567079e507fd69f252859b63e0409]