CVE-2026-100767
published 2026-09-29CVE-2026-100767: Use-after-free in the Networking: Cache component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4…
PriorityP346high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.32%
23.3th percentile
Use-after-free in the Networking: Cache component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
Affected
18 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 157 | Firefox 157 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 115.0 < 115.42.0 | 115.42.0 |
| mozilla | firefox | >= 140.0 < 140.17.0 | 140.17.0 |
| mozilla | firefox | >= 153.0.0 < 153.4.0 | 153.4.0 |
| mozilla | firefox | >= 154.0.0 < 157.0.0 | 157.0.0 |
| mozilla | firefox_esr | < Firefox ESR 115.42 | Firefox ESR 115.42 |
| mozilla | firefox_esr | < Firefox ESR 140.17 | Firefox ESR 140.17 |
| mozilla | firefox_esr | < Firefox ESR 153.4 | Firefox ESR 153.4 |
| mozilla | thunderbird | < Thunderbird 140.17 | Thunderbird 140.17 |
| mozilla | thunderbird | < Thunderbird 157 | Thunderbird 157 |
| mozilla | thunderbird | < Thunderbird 153.4 | Thunderbird 153.4 |
| mozilla | thunderbird | — | — |
| mozilla | thunderbird | >= 140.0 < 140.17.0 | 140.17.0 |
| mozilla | thunderbird | >= 153.0 < 153.4.0 | 153.4.0 |
| mozilla | thunderbird | >= 154.0 < 157.0 | 157.0 |
| rhel10 | firefox-flatpak | — | — |
| rhel10 | thunderbird-flatpak | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vendor_redhat8.8HIGH
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VulDB
Mozilla Firefox 115.41/140.16/153.3/156 Networking Cache use after free (WID-SEC-2026-3654)
vuldb·2026-10-03·CVSS 8.8
CVE-2026-100767 [HIGH] Mozilla Firefox 115.41/140.16/153.3/156 Networking Cache use after free (WID-SEC-2026-3654)
A vulnerability classified as critical was found in Mozilla Firefox 115.41/140.16/153.3/156. Affected by this vulnerability is an unknown functionality of the component Networking Cache. Executing a manipulation can lead to use after free.
The identification of this vulnerability is CVE-2026-100767. The attack may be launched remotely. There is no exploit available.
Upgrading the affected component is advised.
GHSA
Use-after-free in the Networking: Cache component.
ghsa_unreviewed·2026-09-29
CVE-2026-100767 [HIGH] CWE-416 Use-after-free in the Networking: Cache component.
Use-after-free in the Networking: Cache component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
Red Hat
firefox: thunderbird: Use-after-free in the Networking: Cache component
vendor_redhat·2026-09-29·CVSS 8.8
CVE-2026-100767 [HIGH] CWE-416 firefox: thunderbird: Use-after-free in the Networking: Cache component
firefox: thunderbird: Use-after-free in the Networking: Cache component
Use-after-free in the Networking: Cache component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Use-after-free in the Networking: Cache component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Mitigation: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread
Mozilla
Mozilla Foundation Security Advisory 2026-98: CVE-2026-100767
vendor_mozilla·CVSS 8.8
CVE-2026-100767 [HIGH] Mozilla Foundation Security Advisory 2026-98: CVE-2026-100767
Mozilla Foundation Security Advisory 2026-98
CVE: CVE-2026-100767
Product: Firefox ESR
Impact: moderate
Fixed in: Firefox ESR 115.42
Mozilla
Mozilla Foundation Security Advisory 2026-102: CVE-2026-100767
vendor_mozilla·CVSS 8.8
CVE-2026-100767 [HIGH] Mozilla Foundation Security Advisory 2026-102: CVE-2026-100767
Mozilla Foundation Security Advisory 2026-102
CVE: CVE-2026-100767
Product: Thunderbird
Impact: moderate
Fixed in: Thunderbird 140.17
Mozilla
Mozilla Foundation Security Advisory 2026-101: CVE-2026-100767
vendor_mozilla·CVSS 8.8
CVE-2026-100767 [HIGH] Mozilla Foundation Security Advisory 2026-101: CVE-2026-100767
Mozilla Foundation Security Advisory 2026-101
CVE: CVE-2026-100767
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 157
Mozilla
Mozilla Foundation Security Advisory 2026-103: CVE-2026-100767
vendor_mozilla·CVSS 8.8
CVE-2026-100767 [HIGH] Mozilla Foundation Security Advisory 2026-103: CVE-2026-100767
Mozilla Foundation Security Advisory 2026-103
CVE: CVE-2026-100767
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 153.4
Mozilla
Mozilla Foundation Security Advisory 2026-99: CVE-2026-100767
vendor_mozilla·CVSS 8.8
CVE-2026-100767 [HIGH] Mozilla Foundation Security Advisory 2026-99: CVE-2026-100767
Mozilla Foundation Security Advisory 2026-99
CVE: CVE-2026-100767
Product: Firefox ESR
Impact: moderate
Fixed in: Firefox ESR 140.17
Mozilla
Mozilla Foundation Security Advisory 2026-97: CVE-2026-100767
vendor_mozilla·CVSS 8.8
CVE-2026-100767 [HIGH] Mozilla Foundation Security Advisory 2026-97: CVE-2026-100767
Mozilla Foundation Security Advisory 2026-97
CVE: CVE-2026-100767
Product: Firefox
Impact: low
Fixed in: Firefox 157
Mozilla
Mozilla Foundation Security Advisory 2026-100: CVE-2026-100767
vendor_mozilla·CVSS 8.8
CVE-2026-100767 [HIGH] Mozilla Foundation Security Advisory 2026-100: CVE-2026-100767
Mozilla Foundation Security Advisory 2026-100
CVE: CVE-2026-100767
Product: Firefox ESR
Impact: low
Fixed in: Firefox ESR 153.4
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2063680https://www.mozilla.org/security/advisories/mfsa2026-100/https://www.mozilla.org/security/advisories/mfsa2026-101/https://www.mozilla.org/security/advisories/mfsa2026-102/https://www.mozilla.org/security/advisories/mfsa2026-103/https://www.mozilla.org/security/advisories/mfsa2026-97/https://www.mozilla.org/security/advisories/mfsa2026-98/https://www.mozilla.org/security/advisories/mfsa2026-99/
2026-09-29
Published