HIGH
CVE-2026-6758
Published: April 21, 2026· Updated: Apr 22, 2026
7.5
CVSS v3.1
Official Description
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.
Technical Analysis
CVE-2026-6758 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 availability disruption (denial of service), with a CVSS base score of 7.5.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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Official Patches & Advisories
All References (3)
→
https://bugzilla.mozilla.org/show_bug.cgi?id=2013619Permissions Required
→
https://www.mozilla.org/security/advisories/mfsa2026-30/Vendor Advisory
→
https://www.mozilla.org/security/advisories/mfsa2026-33/Vendor Advisory
Quick Facts
CVE IDCVE-2026-6758
CVSS Score7.5 / 10
SeverityHIGH
CISA KEVNo
Affected1 vendor
PublishedApr 21, 2026
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-6758 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.