CVE-2026-6766
published 2026-04-21CVE-2026-6766: Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and…
PriorityP342high7.5CVSS 3.1
AVNACLPRNUINSUCHINAN
EPSS
0.26%
17.2th percentile
Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
Affected
9 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 | — | — |
| 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 |
| rhel10 | firefox-flatpak | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
vendor_redhat7.5HIGH
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Red Hat
firefox: Incorrect boundary conditions in the Libraries component in NSS
vendor_redhat·2026-04-21·CVSS 7.5
CVE-2026-6766 [HIGH] CWE-125 firefox: Incorrect boundary conditions in the Libraries component in NSS
firefox: Incorrect boundary conditions in the Libraries component in NSS
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:
Incorrect boundary conditions in the Libraries component in NSS
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
Package: firefox (Red Hat Enterprise Linux 7) - Affected
Package: firefox (Red Hat Enterprise Linux 8) - Affected
Package: firefox (Red Hat Enterprise Linux 9) - Affected
Mozilla
Mozilla Foundation Security Advisory 2026-34: CVE-2026-6766
vendor_mozilla·CVSS 7.5
CVE-2026-6766 [HIGH] Mozilla Foundation Security Advisory 2026-34: CVE-2026-6766
Mozilla Foundation Security Advisory 2026-34
CVE: CVE-2026-6766
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.10
Mozilla
Mozilla Foundation Security Advisory 2026-30: CVE-2026-6766
vendor_mozilla·CVSS 7.5
CVE-2026-6766 [HIGH] Mozilla Foundation Security Advisory 2026-30: CVE-2026-6766
Mozilla Foundation Security Advisory 2026-30
CVE: CVE-2026-6766
Product: Firefox
Impact: high
Fixed in: Firefox 150
Mozilla
Mozilla Foundation Security Advisory 2026-33: CVE-2026-6766
vendor_mozilla·CVSS 7.5
CVE-2026-6766 [HIGH] Mozilla Foundation Security Advisory 2026-33: CVE-2026-6766
Mozilla Foundation Security Advisory 2026-33
CVE: CVE-2026-6766
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 150
Mozilla
Mozilla Foundation Security Advisory 2026-32: CVE-2026-6766
vendor_mozilla·CVSS 7.5
CVE-2026-6766 [HIGH] Mozilla Foundation Security Advisory 2026-32: CVE-2026-6766
Mozilla Foundation Security Advisory 2026-32
CVE: CVE-2026-6766
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.10
GHSA
GHSA-q6qg-6fmg-jjcv: Incorrect boundary conditions in the Libraries component in NSS
ghsa_unreviewed·2026-04-21
CVE-2026-6766 [HIGH] CWE-754 GHSA-q6qg-6fmg-jjcv: Incorrect boundary conditions in the Libraries component in NSS
Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150 and Firefox ESR 140.10.
No detection rules found.
No public exploits indexed.
2026-04-21
Published