CVE-2026-74940
published 2026-08-18CVE-2026-74940: Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1…
PriorityP352critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.41%
34.7th percentile
Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
Affected
16 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 154 | Firefox 154 |
| mozilla | firefox | < 115.39.0 | 115.39.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 116.0 < 140.14.0 | 140.14.0 |
| mozilla | firefox | >= 141.0 < 154.0.0 | 154.0.0 |
| mozilla | firefox_esr | < Firefox ESR 115.39 | Firefox ESR 115.39 |
| mozilla | firefox_esr | < Firefox ESR 140.14 | Firefox ESR 140.14 |
| mozilla | firefox_esr | < Firefox ESR 153.1 | Firefox ESR 153.1 |
| mozilla | thunderbird | < Thunderbird 153.1 | Thunderbird 153.1 |
| mozilla | thunderbird | < Thunderbird 140.14 | Thunderbird 140.14 |
| mozilla | thunderbird | < Thunderbird 154 | Thunderbird 154 |
| mozilla | thunderbird | < 140.14.0 | 140.14.0 |
| mozilla | thunderbird | — | — |
| mozilla | thunderbird | >= 141.0 < 153.1.0 | 153.1.0 |
| rhel10 | firefox-flatpak | — | — |
| rhel10 | thunderbird-flatpak | — | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat7.5HIGH
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VulDB
Mozilla Firefox prior 115.39/140.14/153.1/154 Text use after free
vuldb·2026-08-23·CVSS 9.8
CVE-2026-74940 [CRITICAL] Mozilla Firefox prior 115.39/140.14/153.1/154 Text use after free
A vulnerability marked as critical has been reported in Mozilla Firefox. This affects an unknown part of the component Text. This manipulation causes use after free.
This vulnerability is handled as CVE-2026-74940. The attack can be initiated remotely. There is not any exploit available.
It is suggested to upgrade the affected component.
GHSA
Use-after-free in the Graphics: Text component.
ghsa_unreviewed·2026-08-18
CVE-2026-74940 Use-after-free in the Graphics: Text component.
Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
Red Hat
firefox: thunderbird: Use-after-free in the Graphics: Text component
vendor_redhat·2026-08-18·CVSS 7.5
CVE-2026-74940 [HIGH] CWE-825 firefox: thunderbird: Use-after-free in the Graphics: Text component
firefox: thunderbird: Use-after-free in the Graphics: Text component
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Use-after-free in the Graphics: Text component
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: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Affected
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
Package: thunderbird (Red Hat Enterprise Linux 6) - Out of support scope
Package: firefox
Mozilla
Mozilla Foundation Security Advisory 2026-74: CVE-2026-74940
vendor_mozilla
CVE-2026-74940 Mozilla Foundation Security Advisory 2026-74: CVE-2026-74940
Mozilla Foundation Security Advisory 2026-74
CVE: CVE-2026-74940
Product: Firefox
Impact: high
Fixed in: Firefox 154
Mozilla
Mozilla Foundation Security Advisory 2026-75: CVE-2026-74940
vendor_mozilla
CVE-2026-74940 Mozilla Foundation Security Advisory 2026-75: CVE-2026-74940
Mozilla Foundation Security Advisory 2026-75
CVE: CVE-2026-74940
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 115.39
Mozilla
Mozilla Foundation Security Advisory 2026-80: CVE-2026-74940
vendor_mozilla
CVE-2026-74940 Mozilla Foundation Security Advisory 2026-80: CVE-2026-74940
Mozilla Foundation Security Advisory 2026-80
CVE: CVE-2026-74940
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-76: CVE-2026-74940
vendor_mozilla
CVE-2026-74940 Mozilla Foundation Security Advisory 2026-76: CVE-2026-74940
Mozilla Foundation Security Advisory 2026-76
CVE: CVE-2026-74940
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.14
Mozilla
Mozilla Foundation Security Advisory 2026-79: CVE-2026-74940
vendor_mozilla
CVE-2026-74940 Mozilla Foundation Security Advisory 2026-79: CVE-2026-74940
Mozilla Foundation Security Advisory 2026-79
CVE: CVE-2026-74940
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.14
Mozilla
Mozilla Foundation Security Advisory 2026-78: CVE-2026-74940
vendor_mozilla
CVE-2026-74940 Mozilla Foundation Security Advisory 2026-78: CVE-2026-74940
Mozilla Foundation Security Advisory 2026-78
CVE: CVE-2026-74940
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 154
Mozilla
Mozilla Foundation Security Advisory 2026-77: CVE-2026-74940
vendor_mozilla
CVE-2026-74940 Mozilla Foundation Security Advisory 2026-77: CVE-2026-74940
Mozilla Foundation Security Advisory 2026-77
CVE: CVE-2026-74940
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 153.1
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2054842https://www.mozilla.org/security/advisories/mfsa2026-74/https://www.mozilla.org/security/advisories/mfsa2026-75/https://www.mozilla.org/security/advisories/mfsa2026-76/https://www.mozilla.org/security/advisories/mfsa2026-77/https://www.mozilla.org/security/advisories/mfsa2026-78/https://www.mozilla.org/security/advisories/mfsa2026-79/https://www.mozilla.org/security/advisories/mfsa2026-80/
2026-08-18
Published