CVE-2026-6776
published 2026-04-21CVE-2026-6776: Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and…
PriorityP337high7.8CVSS 3.1
AVLACLPRNUIRSUCHIHAH
EPSS
0.11%
1.5th percentile
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.
Affected
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 150 | Firefox 150 |
| mozilla | firefox | < 140.10.0 | 140.10.0 |
| mozilla | firefox | < 150.0 | 150.0 |
| mozilla | firefox_esr | < Firefox ESR 140.10 | Firefox ESR 140.10 |
| mozilla | thunderbird | < Thunderbird 140.10 | Thunderbird 140.10 |
| mozilla | thunderbird | < Thunderbird 150 | Thunderbird 150 |
| mozilla | thunderbird | < 140.10.0 | 140.10.0 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vendor_redhat7.8HIGH
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Red Hat
firefox: Incorrect boundary conditions in the WebRTC: Networking component
vendor_redhat·2026-04-21·CVSS 7.8
CVE-2026-6776 [HIGH] CWE-131 firefox: Incorrect boundary conditions in the WebRTC: Networking component
firefox: Incorrect boundary conditions in the WebRTC: Networking component
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:
Incorrect boundary conditions in the WebRTC: Networking component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Mozilla
Mozilla Foundation Security Advisory 2026-30: CVE-2026-6776
vendor_mozilla·CVSS 7.8
CVE-2026-6776 [HIGH] Mozilla Foundation Security Advisory 2026-30: CVE-2026-6776
Mozilla Foundation Security Advisory 2026-30
CVE: CVE-2026-6776
Product: Firefox
Impact: high
Fixed in: Firefox 150
Mozilla
Mozilla Foundation Security Advisory 2026-34: CVE-2026-6776
vendor_mozilla·CVSS 7.8
CVE-2026-6776 [HIGH] Mozilla Foundation Security Advisory 2026-34: CVE-2026-6776
Mozilla Foundation Security Advisory 2026-34
CVE: CVE-2026-6776
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.10
Mozilla
Mozilla Foundation Security Advisory 2026-32: CVE-2026-6776
vendor_mozilla·CVSS 7.8
CVE-2026-6776 [HIGH] Mozilla Foundation Security Advisory 2026-32: CVE-2026-6776
Mozilla Foundation Security Advisory 2026-32
CVE: CVE-2026-6776
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.10
Mozilla
Mozilla Foundation Security Advisory 2026-33: CVE-2026-6776
vendor_mozilla·CVSS 7.8
CVE-2026-6776 [HIGH] Mozilla Foundation Security Advisory 2026-33: CVE-2026-6776
Mozilla Foundation Security Advisory 2026-33
CVE: CVE-2026-6776
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 150
VulDB
Mozilla Firefox up to 149 WebRTC memory corruption (Nessus ID 310350 / WID-SEC-2026-1228)
vuldb·2026-05-21·CVSS 7.8
CVE-2026-6776 [HIGH] Mozilla Firefox up to 149 WebRTC memory corruption (Nessus ID 310350 / WID-SEC-2026-1228)
A vulnerability, which was classified as critical, was found in Mozilla Firefox up to 149. This issue affects some unknown processing of the component WebRTC. Such manipulation leads to memory corruption.
This vulnerability is uniquely identified as CVE-2026-6776. The attack can be launched remotely. No exploit exists.
You should upgrade the affected component.
GHSA
GHSA-cr7m-q2pr-wwq7: Incorrect boundary conditions in the WebRTC: Networking component
ghsa_unreviewed·2026-04-21
CVE-2026-6776 [HIGH] CWE-119 GHSA-cr7m-q2pr-wwq7: Incorrect boundary conditions in the WebRTC: Networking component
Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150 and Firefox ESR 140.10.
No detection rules found.
No public exploits indexed.
2026-04-21
Published