HIGH
CVE-2026-6776
Published: April 21, 2026· Updated: Apr 22, 2026
7.8
CVSS v3.1
Official Description
Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
Technical Analysis
CVE-2026-6776 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
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 7.8.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (5)
→
https://bugzilla.mozilla.org/show_bug.cgi?id=2021770Permissions Required
→
https://www.mozilla.org/security/advisories/mfsa2026-30/Vendor Advisory
→
https://www.mozilla.org/security/advisories/mfsa2026-32/Vendor Advisory
→
https://www.mozilla.org/security/advisories/mfsa2026-33/Vendor Advisory
→
https://www.mozilla.org/security/advisories/mfsa2026-34/Vendor Advisory
Quick Facts
CVE IDCVE-2026-6776
CVSS Score7.8 / 10
SeverityHIGH
CISA KEVNo
Affected1 vendor
PublishedApr 21, 2026
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-6776 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.