CVE-2026-74943
published 2026-08-18CVE-2026-74943: Use-after-free in the Graphics: ImageLib 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
0.57%
45.2th percentile
Use-after-free in the Graphics: ImageLib 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 < 153.1.0 | 153.1.0 |
| 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 140.14 | Thunderbird 140.14 |
| mozilla | thunderbird | < Thunderbird 154 | Thunderbird 154 |
| mozilla | thunderbird | < Thunderbird 153.1 | Thunderbird 153.1 |
| 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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Red Hat
firefox: thunderbird: Use-after-free in the Graphics: ImageLib component
vendor_redhat·2026-08-18·CVSS 7.5
CVE-2026-74943 [HIGH] CWE-825 firefox: thunderbird: Use-after-free in the Graphics: ImageLib component
firefox: thunderbird: Use-after-free in the Graphics: ImageLib 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: ImageLib 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:
Mozilla
Mozilla Foundation Security Advisory 2026-75: CVE-2026-74943
vendor_mozilla
CVE-2026-74943 Mozilla Foundation Security Advisory 2026-75: CVE-2026-74943
Mozilla Foundation Security Advisory 2026-75
CVE: CVE-2026-74943
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 115.39
Mozilla
Mozilla Foundation Security Advisory 2026-79: CVE-2026-74943
vendor_mozilla
CVE-2026-74943 Mozilla Foundation Security Advisory 2026-79: CVE-2026-74943
Mozilla Foundation Security Advisory 2026-79
CVE: CVE-2026-74943
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.14
Mozilla
Mozilla Foundation Security Advisory 2026-78: CVE-2026-74943
vendor_mozilla
CVE-2026-74943 Mozilla Foundation Security Advisory 2026-78: CVE-2026-74943
Mozilla Foundation Security Advisory 2026-78
CVE: CVE-2026-74943
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 154
Mozilla
Mozilla Foundation Security Advisory 2026-76: CVE-2026-74943
vendor_mozilla
CVE-2026-74943 Mozilla Foundation Security Advisory 2026-76: CVE-2026-74943
Mozilla Foundation Security Advisory 2026-76
CVE: CVE-2026-74943
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.14
Mozilla
Mozilla Foundation Security Advisory 2026-74: CVE-2026-74943
vendor_mozilla
CVE-2026-74943 Mozilla Foundation Security Advisory 2026-74: CVE-2026-74943
Mozilla Foundation Security Advisory 2026-74
CVE: CVE-2026-74943
Product: Firefox
Impact: high
Fixed in: Firefox 154
Mozilla
Mozilla Foundation Security Advisory 2026-80: CVE-2026-74943
vendor_mozilla
CVE-2026-74943 Mozilla Foundation Security Advisory 2026-80: CVE-2026-74943
Mozilla Foundation Security Advisory 2026-80
CVE: CVE-2026-74943
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-77: CVE-2026-74943
vendor_mozilla
CVE-2026-74943 Mozilla Foundation Security Advisory 2026-77: CVE-2026-74943
Mozilla Foundation Security Advisory 2026-77
CVE: CVE-2026-74943
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 153.1
VulDB
Mozilla Firefox prior 115.39/140.14/153.1/154 ImageLib use after free
vuldb·2026-08-23·CVSS 9.8
CVE-2026-74943 [CRITICAL] Mozilla Firefox prior 115.39/140.14/153.1/154 ImageLib use after free
A vulnerability classified as critical has been found in Mozilla Firefox. This issue affects some unknown processing of the component ImageLib. Performing a manipulation results in use after free.
This vulnerability was named CVE-2026-74943. The attack may be initiated remotely. There is no available exploit.
It is recommended to upgrade the affected component.
GHSA
Use-after-free in the Graphics: ImageLib component.
ghsa_unreviewed·2026-08-18
CVE-2026-74943 Use-after-free in the Graphics: ImageLib component.
Use-after-free in the Graphics: ImageLib component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2057308https://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