CVE-2026-6754
Description
Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Use-after-free in Mozilla's JavaScript Engine (Firefox/Thunderbird) allows potential code execution; patched in latest versions.
Vulnerability
CVE-2026-6754 is a use-after-free vulnerability in the JavaScript Engine component of Mozilla Firefox and Thunderbird. The root cause is improper memory management, where a freed object is still accessible, leading to memory corruption [1][2].
Exploitation
An attacker can exploit this by crafting malicious JavaScript content that triggers the use-after-free condition. In the Thunderbird product, scripting is disabled when reading email, so exploitation is not possible through email alone but is a risk in browser or browser-like contexts [1][3].
Impact
Successful exploitation could allow an attacker to execute arbitrary code, potentially leading to full system compromise. The vulnerability is rated High severity [2][4].
Mitigation
Mozilla has fixed this vulnerability in Firefox 150, Firefox ESR 115.35 and 140.10, Thunderbird 150, and Thunderbird 140.10. Users are advised to update to these versions [1][4].
AI Insight generated on May 18, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
5cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*+ 1 more
- cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*range: <150.0
- cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*range: <115.35.0
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*+ 1 more
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*range: <140.10.0
- (no CPE)range: <150,<140.10
- Range: <115.35,<140.10
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
6- www.mozilla.org/security/advisories/mfsa2026-30/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-31/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-32/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-33/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-34/nvdVendor Advisory
- bugzilla.mozilla.org/show_bug.cginvdPermissions Required
News mentions
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