CVE-2026-74943: Vulnerability in Mozilla Firefox
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.
AI Analysis
Technical Summary
CVE-2026-74943 is a use-after-free vulnerability affecting the Graphics: ImageLib component in Mozilla Firefox. This type of vulnerability can lead to memory corruption issues. Mozilla fixed this vulnerability in Firefox 154 and Firefox ESR versions 115.39, 140.14, and 153.1. The vendor advisory classifies the impact as high and indicates that the flaw was internally found and patched. There is no CVSS score provided, and no known active exploitation has been reported.
Potential Impact
The vulnerability allows use-after-free conditions in the Graphics: ImageLib component, which can lead to memory corruption and potentially allow an attacker to execute arbitrary code or cause a denial of service. The vendor rates the impact as high. No active exploitation in the wild has been reported at this time.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 154 and Firefox ESR versions 115.39, 140.14, and 153.1. Users and administrators should update to these versions or later to remediate the issue. There is no indication from the vendor advisory that additional mitigation steps are required beyond applying the official updates.
CVE-2026-74943: Vulnerability in Mozilla Firefox
Description
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 software
pkg:github/mozilla/firefox-esrRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-74943 is a use-after-free vulnerability affecting the Graphics: ImageLib component in Mozilla Firefox. This type of vulnerability can lead to memory corruption issues. Mozilla fixed this vulnerability in Firefox 154 and Firefox ESR versions 115.39, 140.14, and 153.1. The vendor advisory classifies the impact as high and indicates that the flaw was internally found and patched. There is no CVSS score provided, and no known active exploitation has been reported.
Potential Impact
The vulnerability allows use-after-free conditions in the Graphics: ImageLib component, which can lead to memory corruption and potentially allow an attacker to execute arbitrary code or cause a denial of service. The vendor rates the impact as high. No active exploitation in the wild has been reported at this time.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 154 and Firefox ESR versions 115.39, 140.14, and 153.1. Users and administrators should update to these versions or later to remediate the issue. There is no indication from the vendor advisory that additional mitigation steps are required beyond applying the official updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:57:44.816Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-74/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-75/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-76/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-77/","vendor":"Mozilla"}]
Threat ID: 6a845504c6e8be03323673b9
Added to database: 08/18/2026, 12:50:12 UTC
Last enriched: 08/18/2026, 13:56:37 UTC
Last updated: 08/19/2026, 00:13:25 UTC
Views: 13
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